Deficit of ß-endorphin neurons in the hypothalamus and high expression of MOR in mesolimbic structures are related to high alcohol consumption in outbred rats.

Clinical studies have postulated that ß-endorphin deficiency generates excessive alcohol consumption, and it has been shown that the reduction of ß-endorphin neurons increases alcohol intake in animal models. The ß-endorphin produce their rewarding effect when they act mainly on the µ-opioid receptors (MOR) located in mesolimbic structures. Thus, it is possible that individual differences in these components of the endogenous opioid system are related to different levels of alcohol consumption. The present study thus examines the relation between two levels of alcohol consumption and intrinsic characteristics of the components of the opioid system in outbred Wistar rats that were not genetically selected. We analyzed the number of ß-endorphin-positive neurons in the arcuate nucleus (ArN) and the expression of µ-opioid receptors (MOR) in regions of the reward system, such as the nucleus accumbens (NAc), amygdala (Amy), and ventral tegmental area (VTA) in outbred rats with low (LC) or high (HC) voluntary alcohol consumption. Findings showed that the HC rats had a lower number of ß-endorphin-positive neurons in the hypothalamic ArN and a higher expression of MOR in the NAc and VTA, compared to the LC rats. No changes in the expression of MOR in the Amy were observed between the two groups. Results suggest that intrinsic variability in the number of ß-endorphin neurons and in the expression of MOR in the LC and HC rats could explain their different patterns for alcohol intake.

Buccal dental-microwear and feeding ecology of Early Pleistocene Theropithecus oswaldi from Cueva Victoria (Spain).

Despite the scarcity of fossil specimens of Theropithecus oswaldi in Eurasia, its presence out of Africa attests to the great dispersal of this Papionini genus during the Early Pleistocene. In the present study, we analyze the buccal dental microwear of T. oswaldi (T. o. leakeyi) fossil specimens from Cueva Victoria (Southeastern Spain). This analysis is the first characterization of the feeding ecology of T. oswaldi in Europe. The buccal microwear pattern of the molar and premolar teeth of T. oswaldi from Cueva Victoria shows great similarities to that observed for the extant frugivorous forest-dwelling Mandrillus sphinx and mangabeys (Cercocebus sp.)-both species adapted to durophagous dietary habits-while significantly different from that observed for the gramnivorous Theropithecus gelada. These results suggest that T. oswaldi from Cueva Victoria could have exploited both hard-shelled fruits or seeds and succulent fruits from open and forested Mediterranean ecosystems.

Differential expression of µ-opioid receptors in the nucleus accumbens, amygdala and VTA depends on liking for alcohol, chronic alcohol intake and estradiol treatment.

Affectations of the opioid system have been related to exacerbated alcohol consumption. The objectives of this work were to assess whether a deficit of ß-endorphinergic neurons differentially affects alcohol intake in female rats with low (LC) and high alcohol consumption (HC), and to determine changes in the µ-opioid receptors (MOR) related to alcohol consumption and chronic exposure to alcohol in structures of the mesolimbic system. Female wild-type rats were selected according to their baseline alcohol intake levels and then exposed to chronic voluntary alcohol consumption after a single injection of either the vehicle or estradiol valerate (EV) to produce a ß-endorphin neuronal deficit. Changes in alcohol consumption and MOR expression levels were assessed in the nucleus accumbens (NAc), amygdala (Amy) and ventral tegmental area (VTA) at 5 and 10 weeks after EV treatment. The LC rats increased alcohol intake from baseline to the initial weeks after EV treatment and this consumption remained stable throughout the studied period. In contrast, alcohol consumption increased steadily over time in the HC rats. The HC vehicle rats had a 38% higher MOR protein expression in the NAc than the LC vehicle rats. In addition, chronic alcohol consumption increased MOR expression in the Amy regardless of consumption level, whereas EV treatment produced a decrease in MOR expression in the VTA in all groups. These results suggest intrinsic differences in MOR expression related to alcohol consumption levels. Also, the EV treatment and chronic exposure to alcohol produced adaptive changes in MOR expression.

A multi-centre cohort study investigating the outcome of synovial contamination or sepsis of the calcaneal bursae in horses treated by endoscopic lavage and debridement.

BACKGROUND: Previous studies investigating factors associated with survival following endoscopic treatment of contamination/sepsis of the calcaneal bursa are limited. OBJECTIVES: To investigate the factors associated with survival in horses with contamination/sepsis of the calcaneal bursae treated endoscopically and to describe the bacterial isolates involved in the synovial infections. STUDY DESIGN: Retrospective analysis of clinical records. METHODS: Medical records from 128 horses with contamination/sepsis of the calcaneal bursae treated by endoscopic lavage at seven equine hospitals were reviewed. A follow-up questionnaire was used to determine survival and return to athletic performance. Descriptive statistics and Cox proportional hazards survival models were used to determine factors associated with survival. RESULTS: Horses underwent one (n = 107), two (n = 19), or three (n = 2) surgeries. Survival to hospital discharge was 84.4%. Univariable survival analysis revealed that administration of systemic antimicrobials prior to referral was associated with reduced mortality (hazard ratio, [HR] 0.41, 95% CI 0.18-0.91, P = 0.03). Increased mortality was associated with bone fracture/osteomyelitis (HR 2.43, 95% CI 1.12-5.26, P = 0.03), tendon involvement (≥30% cross sectional area) (HR 3.78 95% CI 1.78-8.04, P = 0.001), duration of general anaesthesia (HR 1.01, 95% CI 1.00-1.02, P = 0.04), post-operative synoviocentesis (HR 3.18, 95% CI 1.36-7.43, P = 0.006) and post-operative wound dehiscence (HR 2.5, 95% CI 1.08-5.65, P = 0.04). Multivariable Cox proportional hazards model revealed reduced mortality after systemic antimicrobial administration prior to referral (HR 0.25, 95% CI 0.11-0.60, P = 0.002) and increased mortality with tendinous involvement (≥30% cross-sectional area) (HR 7.92, 95% CI 3.31-19.92, P<0.001). At follow-up (median 30 months, range 0.25-13 years, n = 70) 87.1% horses were alive, 7.1% had been euthanised due to the calcaneal injury and 5.7% had been euthanised for unrelated reasons. From 57 horses with athletic performance follow-up, 91.2% returned to the same/higher level of exercise, 5.3% to a lower level and 3.5% were retired due to persistent lameness of the affected limb. MAIN LIMITATIONS: Retrospective study and incomplete follow-up. CONCLUSION: Endoscopic treatment of contamination/sepsis of the calcaneal bursae has an 84% survival rate to hospital discharge. Tendinous involvement reduced survival whilst systemic antimicrobials administration prior to referral improved survival.

Fracture of the medial intercondylar eminence of the tibia in horses treated by arthroscopic fragment removal (21 horses).

BACKGROUND: Fractures of the medial intercondylar eminence of the tibia (MICET) are scarcely reported in horses. OBJECTIVES: To report the clinical and diagnostic findings, surgical treatment and outcome in a series of horses presented with MICET fracture and treated with arthroscopic fragment removal. STUDY DESIGN: Multicentre retrospective case series. METHODS: Case records of horses diagnosed with MICET fractures that had undergone surgical treatment were reviewed. Follow-up information was obtained from re-examination visits and/or owners. RESULTS: Twenty-one cases were identified at 9 equine hospitals between 2004 and 2016. A history of trauma and acute onset of lameness was reported in 12 horses. All cases underwent fracture removal via arthroscopy of the medial femorotibial joint. The cranial cruciate ligament was intact in 6 horses and damaged in 15 horses (damage was ≤25% [n = 9], 25-50% [n = 4] or ≥50% [n = 2] of the cross-sectional area). The cranial ligament of the medial meniscus was damaged in 11 horses (≤25% [n = 8], 25-50% [n = 3]). The medial meniscus was damaged in 5 horses and articular cartilage damage was identified in 14 horses (mild [n = 8], moderate [n = 6]). Follow-up information (median 14 months; 4 months-6 years) was available for 20 cases; 2 horses were sound but convalescing; 13 horses were sound and returned to their previous or expected use. Of the 4 horses with the most severe changes to the articular soft tissue structures, 2 remained lame and 2 were subjected to euthanasia because of persistent lameness. MAIN LIMITATIONS: The retrospective, multicentre nature of this study and the limited number of horses are the main limitations. CONCLUSIONS: Fractures of the MICET are commonly associated with a traumatic event. Prompt diagnosis and early arthroscopic removal of the fracture are recommended.

Local anaesthetics or their combination with morphine and/or magnesium sulphate are toxic for equine chondrocytes and synoviocytes in vitro.

BACKGROUND: Chondrotoxic effects of local anaesthetics are well reported in humans and some animal species but knowledge on their toxic effects on synoviocytes or equine chondrocytes or the effects on cellular production of inflammatory cytokines is limited. The purpose of this study was to evaluate the in vitro effects of local anaesthetics, morphine, magnesium sulphate (MgSO4) or their combinations on cell viability and pro-inflammatory cytokine gene expression of equine synoviocytes and chondrocytes. Equine synoviocytes and cartilage explants harvested from normal joints in a co-culture system were exposed to mepivacaine (4.4 mg/ml), bupivacaine (2.2 mg/ml), morphine (2.85 mg/ml) and MgSO4 (37 mg/ml) alone or each local anaesthetic plus morphine or MgSO4 or both together. Chondrocyte and synoviocyte cell viability was assessed by CellTiter-Glo Luminescent Cell Viability Assay. Synoviocyte gene expression of IL-1ß, IL-6 or TNF-α was measured and compared using the ∆∆CT method. RESULTS: Morphine alone, MgSO4 alone or their combination did not alter cell viability or the expression of IL-1ß, IL-6 or TNF-α. However, local anaesthetics alone or in combination with morphine and/or MgSO4 reduced cell viability and increased the gene expression of IL-1ß, IL-6 or TNF-α. Single short exposure to local anaesthetics is toxic to both chondrocytes and synoviocytes and their combination with morphine and/or MgSO4 enhanced the cytotoxic effects. CONCLUSIONS: This in vitro study gives further evidence of the absence of cytotoxic effects of morphine alone, MgSO4 alone or their combination on normal articular tissues. However, local anaesthetics alone or in combination with morphine and/or MgSO4 have cytotoxic effects on equine articular tissues.

Prevalence and antimicrobial susceptibility of bacterial isolates from horses with synovial sepsis: A cross-sectional study of 95 cases.

Bacterial culture and antimicrobial susceptibility testing of septic synovial samples allows instigation of targeted antimicrobial therapy; however, bacterial culture takes more than 24 h and has low sensitivity. This study aimed to identify the most frequently cultured bacteria and their antimicrobial susceptibility profile from septic synovial samples in our referral equine hospital, to allow recommendations regarding appropriate initial antimicrobial therapy prior to culture results. Hospital records for all horses with synovial sepsis and a synovial sample submitted to the microbiology laboratory between 2004 and 2013 were retrieved (n= 379 samples). One horse had positive cultures from more than one synovial structure, and two horses had positive cultures obtained from repeat samples. Overall, 114 bacterial isolates were obtained. Gram-positive bacteria were isolated in 75% of cases, of which 22% were haemolytic Staphylococcus spp., and 52% were Staphylococcus aureus including two multidrug-resistant isolates. Gram-negative bacteria were isolated from 25% of cases. Anaerobic Clostridium spp. was isolated in 3% of cases. Of the first line antimicrobials, oxytetracycline and doxycycline were effective against 70-100% of the Gram-positive bacteria and 20-100% of the Gram-negative organisms, whilst trimethoprim-sulphamethoxazole and gentamicin efficacy ranged between 50% and 88% for both Gram-positive and Gram-negative bacteria. Of the equine protected antimicrobials, ceftiofur was effective against 70-90% of all bacterial isolates whilst 80% of isolates were susceptible to enrofloxacin. These results indicate that tetracyclines, trimethoprim-sulphamethoxazole or gentamicin may be suitable first-line antimicrobials for treatment of synovial sepsis cases while awaiting laboratory results, findings which support current recommendations for antimicrobial stewardship in equine medicine.

Effect of repeated through-and-through joint lavage on serum amyloid A in synovial fluid from healthy horses.

The objective of this study was to evaluate the effect of through-and-through joint lavage on systemic and synovial serum amyloid A (SAA), total protein, nucleated cell count and percentage of neutrophils in the synovial fluid of six healthy horses. A prospective experimental study was performed where one healthy tarsocrural joint of each horse was randomly assigned to receive repeated through-and-through joint lavage at 0, 48 and 96 h. Synovial fluid and blood samples were collected at 0 (baseline), 24, 48, 72, 96 and 120 h. Systemic and synovial SAA, total protein, nucleated cell count and percentage of neutrophils were measured and compared to baseline. Concentrations of systemic and synovial SAA percentage of neutrophils were not increased from baseline in contrast to total protein and nucleated cell counts (except for nucleated cell count at 96 h). In conclusion, repeated through-and-through joint lavage did not affect synovial SAA concentrations in horses; however, synovial total protein and nucleated cell count values increased. Some of the total protein and nucleated cell count values observed in this study were within the range reported for septic arthritis 24 h after joint lavage. Hence, synovial SAA may be a valuable marker to evaluate the clinical progression of septic joints after through-and-through joint lavage. Clinical studies evaluating synovial fluid SAA concentrations while treating synovial sepsis with through-and-through joint lavage are warranted.

Clinical and pharmacokinetic effects of regional or general anaesthesia on intravenous regional limb perfusion with amikacin in horses.

REASONS FOR PERFORMING STUDY: Antimicrobial i.v. regional limb perfusion (IV-RLP) is clinically performed on anaesthetised or sedated horses with or without regional anaesthesia. To date, no scientific data are available on the clinical and pharmacokinetic effects of these anaesthetic protocols on antimicrobial IV-RLP, which is believed to result in better tourniquet efficiency due to decreased movement. OBJECTIVE: To determine the effects of regional or general anaesthesia on the clinical and synovial pharmacokinetic parameters of amikacin administered by IV-RLP to horses. STUDY DESIGN: Experimental crossover study. METHODS: Eight healthy horses received 4 treatments of amikacin IV-RLP in a randomised, blinded, crossover design: standing sedation without regional anaesthesia (CNT); standing sedation with i.v. regional anaesthesia; standing sedation with perineural regional anaesthesia (PNA); or general anaesthesia. Synovial fluid amikacin concentrations were measured over 24 h and regional pharmacokinetic parameters calculated. Heart and respiratory rates, visual analogue scale of discomfort, number of times the limb was lifted and number of additional sedations administered were recorded. Analysis of variance crossover analysis was applied with significance level at P < 0.05. RESULTS: Amikacin concentrations and regional pharmacokinetic parameters did not differ significantly among treatments. Visual analogue scores (mean ± s.d.) were significantly lower with PNA (19 ± 15) vs. i.v. regional anaesthesia (69 ± 36) or CNT (81 ± 13; P < 0.001). Significantly less lifting of the limb (mean ± s.d.) occurred with PNA (20 ± 20) vs. CNT (54 ± 22; P < 0.04). CONCLUSIONS: Perineural regional anaesthesia before IV-RLP was most effective in providing comfort to standing, sedated horses without significantly affecting the regional pharmacokinetic parameters of amikacin. High variability of synovial amikacin concentrations was present. The use of general anaesthesia for IV-RLP is not justified based on this study.

Medullary decompression of the radius as treatment for lameness in a horse.

Increased intraosseous pressure (IOP) is a well-characterized source of pain in humans that can be successfully treated by medullary decompression. This report describes the clinical and diagnostic findings, treatment and successful outcome of a horse with a four week long, non-weight bearing lameness secondary to suspected traumatically-induced increased IOP in the left radius. Scintigraphic examination characterized by severe increase in radiopharmaceutical uptake within the affected radius aided in the initial localization of the source of lameness. Decompression of the affected radius was performed by drilling two 3.2 mm tracts through the lateral bone cortex into the medullary cavity. Intramedullary pressure in the radius was measured (37-39 mmHg). Dramatic clinical improvement was observed after surgical decompression of the affected bone and the horse showed full recovery and returned to previous exercise use by 12 months after treatment. Gradual decrease in radial radiopharmaceutical uptake was observed during the following year. Increased IOP should be considered as a cause of lameness in horses and scintigraphic examination may aid in its diagnosis. Medullary decompression may be a successful treatment in some cases.

Spontaneous lun lobe torsion in a mixed-breed dog followed by an apendicular bone nooplasm

Se describe el caso de un canino mestizo hembra de ocho años de edad que presentó historia de diez días de letargia, anorexia, pérdida de peso, vómito ocasional, tos esporádica y dificultad respiratoria; los hallazgos clínicos, radiográficos y ultrasonográficos sugirieron como diagnóstico diferencial más probable torsión lobar pulmonar del lóbulo medio derecho, lo cual se confirmó mediante toracotomía exploratoria. El manejo terapéutico incluyó resección del lóbulo afectado; no se identificó ninguna etiología subyacente. La paciente tuvo una recuperación completa de la torsión lobar; sin embargo, dos semanas después de la cirugía presentó claudicación severa del miembro anterior derecho y se encontraron hallazgos radiográficos compatibles con neoplasia ósea en la epífisis proximal del húmero. Por decisión de los propietarios sólo se realizó manejo analgésico y un mes después se practicó eutanasia debido a una posible metástasis pulmonar. Es posible que la neoplasia y posible metástasis se tratasen de eventos concomitantes sin relación causa-efecto; sin embargo, pudo haber existido una asociación entre un proceso estresante y traumático (la torsión pulmonar) con el desarrollo y manifestación de una patología oncológica subyacente.

In this report, the case of a mixed-breed, female intact, eight-year- old dog, that was presented with a ten-day history of lethargy, anorexia, weight loss, occasional vomiting, coughing and sporadic dispnea is described; the clinical, radiographic and ultrasonographic findings suggested as the most likely diagnosis a lung lobe (right middle) torsion, which was confirmed by means of an exploratory thoracotomy; the therapy included resection of the affected lobe; no underlying etiology was identified. The patient recovered fully from the lobar torsion; however, two weeks after surgery the dog showed severe right forelimb lameness and the radiographic findings suggested a bone tumor in the proximal epiphysis of the humerus; the owners allowed only analgesic therapy and one month later the patient was euthanized due to a possible lung metastases; it is possible that the neoplasm and the metastases were concomitant events without a cause-effect relationship; however, there might also have been an association between a traumatic and stressing process (the lung torsion) with the development of an underlying oncologic process.

Effects of repeated intra-articular administration of amikacin on serum amyloid A, total protein and nucleated cell count in synovial fluid from healthy horses.

REASONS FOR PERFORMING STUDY: Serum amyloid A (SAA) in synovial fluid has recently been used as a marker for septic arthritis in horses but the effects of repeated intra-articular (IA) administration of amikacin on synovial SAA concentrations are unknown. OBJECTIVES: To report the effect of repeated IA administration of amikacin on SAA, total protein (TP), nucleated cell count (NCC) and differential NCC in synovial fluid of healthy equine joints. METHODS: A controlled, 2 period crossover study was performed on 5 clinically healthy horses. Each intercarpal joint received one of 2 treatments every 48 h for 5 consecutive times: arthrocentesis alone (control group) or arthrocentesis combined with IA administration of 500 mg of amikacin (treatment group). Clinical and lameness examinations were performed daily. Serum SAA and synovial SAA, TP, NCC and differential NCC were measured and statistically compared. Significance level was set at P < 0.05. RESULTS: Horses remained healthy and nonlame throughout the study. Baseline values for all variables were not significantly different between groups. Values for TP in the treatment group were significantly higher than in the control group after the first sample (P < 0.05). In both groups NCC increased significantly (P < 0.05) after the first sample. No significant changes were identified in differential NCC. In both groups, all synovial and most serum SAA concentrations remained below the lower limit of quantification. CONCLUSIONS: Repeated IA administration of amikacin caused increased values of TP and NCC in synovial fluid, with some TP concentrations falling within the range reported for septic arthritis. In contrast, synovial SAA concentrations did not increase in either group. POTENTIAL RELEVANCE: Synovial SAA could serve as a more reliable marker than TP and NCC when evaluating a joint previously sampled or treated with amikacin.

Hipoadrenocortiiismo primario canino: reporte de caso / Canine priary hyypoadrenocorticism: case report

Un canino macho Cocker Spaniel de 6 meses de edad fue presentado a la Clínica para Pequeños Animales de la Universidad Nacional de Colombia, con historia de vómito y diarrea de una semana de duración. El paciente presentaba hiperkalemia, y los electrocardiogramas realizados fueron compatibles con este hallazgo. El diagnóstico de hipoadrenocorticismo primario fue confirmado mediante la realización de una prueba de estimulación con ACTH. Posteriormente a la muerte súbita del paciente, el examen microscópico de las glándulas adrenales reveló cambios histológicos compatibles con la enfermedad de Addison. El hipoadrenocorticismo primario es un desorden endocrino poco común que afecta principalmente pacientes caninos; está caracterizado por la destrucción inmunomediada de las cortezas adrenales, lo cual conduce a deficiencia de glucocorticoides, mineralocorticoides y hormonas sexuales adrenales. La historia de los pacientes afectados es variable y los signos clínicos son usualmente inespecíficos; las pruebas de laboratorio, por lo general, revelan hiperkalemia e hiponatremia, resultantes de la pérdida de la secreción de aldosterona. La historia, el examen clínico, la ecografía abdominal y los hallazgos de laboratorio pueden indicar enfermedad de Addison, sin embargo, la prueba de estimulación con hormona adrenocorticotrópica (ACTH) es considerada como la prueba de oro para el diagnóstico definitivo de la entidad. La enfermedad de Addison no tiene cura, pero puede ser manejada con terapia médica para reemplazar las deficiencias de mineralocorticoides y glucocorticoides.

Six month old, male Cocker Spaniel was presented to the Small Animal Clinic at the Universidad Nacional de Colombia with a one week history of vomiting and diarrhea. The patient was hyperkalemic and the electrocardiogram results were consistent with this finding. The diagnosis of primary hypoadrenocorticism was confirmed by performing an ACTH stimulation test. Following the patient’s sudden death, micros copic examination of the adrenal glands revealed histologic changes consistent with Addison`s disease. Primary hypoadrenocorticism is an uncommon endocrine disorder that primarily affects canine patients. The disorder is caracterized by the immune-mediated destruction of the adrenal cortices, resulting in mineralocorticoid, glucocorticoid and adrenal sex hormone deficiencies. Patient history is variable and clinical signs are often nonspecific; laboratory testing commonly reveals hyperkalemia and hyponatremia resulting from lack of aldosterone secretion. Clinical history, physical exam, abdominal ultrasound and laboratory findings may indicate Addison disease, however, the adrenocorticotrophic hormone (ACTH) stimulation test is considered to be the gold standard for definitive diagnosis of primary hypoadrenocortisism. Addison disease is not curable but can be managed with pharmaceutical therapy that replaces the mineralocorticoids and glucocorticoids deficiency.

[Arterial hypertension at a crossroads: the search for an operative definition]. / Hipertensión arterial en su encrucijada: a la búsqueda de una definición operativa.

Hypertension (HT) is recognized as one of the major risk factors for vascular damage. Although current guidelines recommend an aggressive drug treatment with blood pressure control goals ever lower, the prevalence of uncontrolled hypertension is still apparently high. It is often forgotten that BP is a very labile hemodynamic parameter, which requires a correct methodology measurement that meets only rarely, leading to a misdiagnosis and wrong hypertensive monitoring. Even being an arbitrary limit the definition of HT has been set at 140/90 mmHg, based on casual BP taken in the office. This register itself can provide useful information beyond systolic and diastolic values, and with a certain hemodynamic meaning (pulse pressure and mean blood pressure). For a proper diagnosis of hypertensive patients is essential to enhance measure BP in any area with an strict methodology, and to incorporate into clinical practice new techniques such as 24 hours MAPA and AMPA at home, which still require definition of specific reference objectives. The application of these techniques has led to the emergence of several subgroups of hypertensive patients, such as white-coat hypertension and masked hypertension, which have their peculiarities in relation to the therapeutic management and prognosis. These techniques, together with the publication of new clinical trials using criteria of evidence, have led to the review of the Guidelines for the management of hypertension by modifying the limits of BP for some special clinical situations, and changing the paradigm of the lowest BP is the best, by that of: as early and more associated vascular risk factors were controlled it's better.

Adsorption mechanisms of metal cations from water on an oxidized carbon surface.

Adsorption of Cr(III), Mn(II), Cu(II) and Zn(II) on an oxidized activated carbon cloth was studied. Its surface chemistry was characterized by potentiometric titration. This technique revealed the amount of surface oxygen functionalities and their acidity constant distribution. The acidity constant range involved in the metal cation adsorption was obtained from this distribution. Metal cation adsorption increased with higher adsorption temperature due to the increase in the negative surface charge of the oxidized activated carbon. Adsorption was by proton exchange and the number, amount and strength of the surface acid groups involved could be obtained. The proton exchange was by an inner-sphere or outer-sphere surface metal complex formation mechanism. In the case of divalent cation adsorption, the increase in temperature changed the adsorption mechanism from outer-sphere to inner-sphere. However, the adsorption mechanism of Cr(III) was outer-sphere and independent of temperature. Adsorption capacity augmented with the increase in the charge-to-size ratio of the hexa-aquo cations. In addition, the adsorption capacity of divalent cations increased with the rise in stability of the surface metal complex formed.

Batch and column adsorption of herbicide fluroxypyr on different types of activated carbons from water with varied degrees of hardness and alkalinity.

There has been little research into the effects of the water hardness and alkalinity of surface waters on the adsorption of herbicides on activated carbons. The aim of this study was to determine the influence of these water characteristics on fluroxypyr adsorption on different activated carbons. At low fluroxypyr surface concentrations, the amount adsorbed from distilled water was related to the surface hydrophobicity. Surface area of carbons covered by fluroxypyr molecules ranged from 60 to 65%. Variations in fluroxypyr solubility with water hardness and alkalinity showed a salting-in effect. Calcium, magnesium and bicarbonate ions were adsorbed to a varied extent on the activated carbons. The presence of fluroxypyr in solution decreased their adsorption due to a competition effect. K(F) from the Freundlich equation linearly increased with water hardness due to salt-screened electrostatic repulsions between charged fluroxypyr molecules. The amount adsorbed from distilled water was largest at high fluroxypyr solution concentrations, because there was no competition between inorganic ions and fluroxypyr molecules. The column breakthrough volume and the amount adsorbed at breakthrough were smaller in tap versus distilled water. Carbon consumption was lower with activated carbon cloth than with the use of granular activated carbon.

Testing hypotheses of dietary reconstruction from buccal dental microwear in Australopithecus afarensis.

A recent study of occlusal microwear in Australopithecus afarensis described this species as an opportunistic dweller, living in both forested and open environments and greatly relying on fallback resources and using fewer food-processing activities than previously suggested. In the present study, analysis of buccal microwear variability in a sample of A. afarensis specimens (n=75 teeth) showed no significant correlations with the ecological shift that took place around 3.5Ma in Africa. These results are consistent with the occlusal microwear data available. In fact, significant correlations between buccal and occlusal microwear variables were found. However, comparison of the buccal microwear patterns showed clear similarities between A. afarensis and those hominoid species living in somewhat open environments, especially the Cameroon gorillas. A diet based mainly on succulent fruits and seasonal fallback resources would be consistent with the buccal microwear patterns observed.

Adsorption and thermal desorption of the herbicide fluroxypyr on activated carbon fibers and cloth at different pH values.

Adsorption of fluroxypyr was studied at pH values between 2 and 10 and at temperatures of 298 and 313 K. Adsorption capacity decreased when the solution pH increased. This was explained by changes in fluroxypyr solubility and in dispersive and electrostatic adsorbent-adsorbate interactions with the increase in pH. The highest adsorption was found at pH 2, when the solubility was the lowest and only dispersive interactions operated. An increase in temperature produced a decrease in adsorption capacity. Thermal desorption of fluroxypyr up to 1073 K left a residue on the carbon surface, which increased with higher adsorption pH. Differential thermogravimetry (DTG) profiles showed two desorption peaks at pH values of 2 and 4 and only one peak at pH values of 7 and 10. The appearance of one or two peaks may be related to the type of adsorbate-adsorbent interactions established during adsorption. The predominance of electrostatic interactions favours the strongly bound or chemisorbed fluroxypyr. One important conclusion is that the highest amounts of fluroxypyr are adsorbed and thermally desorbed when there are only non-electrostatic interactions between fluroxypyr molecules and carbon surface. Activation desorption energy and pre-exponential factor were obtained from the shift in temperature of desorption peaks with higher heating rate.

Elbow joint luxation in a 1-month-old foal.

This paper reports on luxation of the elbow joint without concomitant fracture in a 1-month-old foal. Conservative treatment, with closed reduction and full-limb bandaging, including caudal and lateral splints, seemed successful initially, however, failed to provide enough stability and luxation recurred, and open reduction and surgical placement of prosthetic collateral ligaments was required. Luxation of the elbow joint should be considered when acute non-weight bearing forelimb lameness occurs associated with pain and swelling in the area of the elbow in young foals. Closed reduction failed to provide sufficient joint stability.