Dust outpaces bedrock in nutrient supply to montane forest ecosystems.

Dust provides ecosystem-sustaining nutrients to landscapes underlain by intensively weathered soils. Here we show that dust may also be crucial in montane forest ecosystems, dominating nutrient budgets despite continuous replacement of depleted soils with fresh bedrock via erosion. Strontium and neodymium isotopes in modern dust show that Asian sources contribute 18-45% of dust deposition across our Sierra Nevada, California study sites. The remaining dust originates regionally from the nearby Central Valley. Measured dust fluxes are greater than or equal to modern erosional outputs from hillslopes to channels, and account for 10-20% of estimated millennial-average inputs of bedrock P. Our results demonstrate that exogenic dust can drive the evolution of nutrient budgets in montane ecosystems, with implications for predicting forest response to changes in climate and land use.

Methane flux in non-wetland soils in response to nitrogen addition: a meta-analysis.

The controls on methane (CH4) flux into and out of soils are not well understood. Environmental variables including temperature, precipitation, and nitrogen (N) status can have strong effects on the magnitude and direction (e.g., uptake vs. release) of CH4 flux. To better understand the interactions between CH4-cycling microorganisms and N in the non-wetland soil system, a meta-analysis was performed on published literature comparing CH4 flux in N amended and matched control plots. An appropriate study index was developed for this purpose. It was found that smaller amounts of N tended to stimulate CH4 uptake while larger amounts tended to inhibit uptake by the soil. When all other variables were accounted for, the switch occurred at 100 kg N x ha(-1) x yr(-1). Managed land and land with a longer duration of fertilization showed greater inhibition of CH4 uptake with added N. These results support the hypotheses that large amounts of available N can inhibit methanotrophy, but also that methanotrophs in upland soils can be N limited in their consumption of CH4 from the atmosphere. There were interactions between other variables and N addition on the CH4 flux response: lower temperature and, to a lesser extent, higher precipitation magnified the inhibition of CH4 uptake due to N addition. Several mechanisms that may cause these trends are discussed, but none could be conclusively supported with this approach. Further controlled and in situ study should be undertaken to isolate the correct mechanism(s) responsible and to model upland CH4 flux.

Early results of the modified Peterson bunion procedure for adolescent hallux valgus.

Adolescent hallux valgus has a high recurrence rate after conventional surgical corrections. Excellent results have been reported with a double osteotomy of the first metatarsal fixed with a 3/16" transarticular pin. The present study reports the early results of using a medial plate and screws with an osteoperiosteal distally based flap to correct metatarsophalangeal joint subluxation, decrease recurrence from laxity in the medial capsular repair, and avoid intra-articular damage. The study included 18 feet in 16 patients (8 males, 8 females). All osteotomies healed primarily without complications, though there was recurrence in 3 undercorrected feet (2 patients). The average preoperative hallux valgus angle of 34 degrees was reduced to 16 degrees at a minimum 1-year follow-up. The average intermetatarsal angle improved from 14 degrees (before operation) to 6 degrees. No patient has requested plate removal.

Sensitivity and specificity of an improved rapid latex agglutination test for identification of methicillin-sensitive and -resistant Staphylococcus aureus isolates.

The performance of a second-generation rapid agglutination kit, Slidex Staph Plus (SSP; bioMérieux), was compared to those of the Slidex Staph (SS; bioMérieux), Staphaurex (SRX; Murex Diagnostics), and BBL Staphyloslide (BBL; Becton Dickinson) kits by using 508 clinical isolates composed of 150 methicillin-sensitive Staphylococcus aureus (MSSA) organisms, 154 methicillin-resistant S. aureus (MRSA) organisms, and 204 non-S. aureus Staphylococcus spp. Of the 508 isolates tested, 75% were fresh clinical isolates, with the remainder taken from five different freezer collections. All four agglutination tests had comparable sensitivities for MSSA and MRSA. However, the SS kit was significantly less specific (93.1%) than the three other tests (P > 0.05, McNemar test). These results demonstrate that the new rapid latex agglutination kit, SSP, was more specific for the identification of S. aureus than the previous version and performed comparably to the SRX and BBL kits.

[Relationship between maternal weight gain and birthweight] / Relação entre ganho de peso materno e peso do recém-nascido.

OBJECTIVE: To investigate the influence of gestational weight gain on birthweight of the newborn, in order to clarify if this weight increment results in heavier newborn. METHODS: Retrospective cohort in a tertiary level private institution that attends a high income population of São Paulo - Brazil; inclusion of all the mother-newborn pairs with complete data (2275) in the Cadastro de Informações Perinatais (CIP) in the software EPI 6; from February/95 till June/96.RESULTS: Gestational weight gain between 12 and 20 kg resulted in a greater number of newborn with birthweights between 3000 and 3499g. Pregnancies with a weight gain below or equal 10 kg correlated with newborn of low birthweight (Odds ratio= 1.81; CI= 1.20-2.73; 95% of significance). Gestational gain beneath or equal to 12 kg had a greater risk of a newborn with insufficient weight - 2499< birthweight < 3000g - (Odds ratio= 1.47; CI= 1.19-1.81; 95% of significance). Gestational gain above 16 kg did not correlate with increase in birthweight.CONCLUSIONS: The gestational weight gain of 12 kg is the minimum increase of weight in order that the newborn is over 3000g. The gestational weight gain above 16 kg did not increase birthweight. The high social economic level was not sufficient to avoid low birthweight or insufficient weight at birth.

When exemplification fails: hypocrisy and the motive for self-integrity.

Two experiments investigated how the dissonance that follows a hypocritical behavior is reduced when 2 alternatives are available; a direct strategy (changing behavior to make it less hypocritical) or an indirect strategy (the affirmation of an unrelated positive aspect of the self). In Experiment 1, after dissonance was aroused by hypocrisy, significantly more participants chose to reduce dissonance directly, despite the clear availability of a self-affirmation strategy. In Experiment 2, participants again chose direct resolution of their hypocritical discrepancy, even when the opportunity to affirm the self held more importance for their global self-worth. The discussion focuses on the mechanisms that influence how people select among readily available strategies for dissonance reduction.

Orthopedic disability, conformity, and social support.

The relation between physical disability, social support, and conformist behavior was tested in two studies. The first compared the conforming responses of persons who had orthopedic disabilities with those of able-bodied individuals and correlated perceived social support of those with the disability with their tendency to conform. The second was an experimental study in which university students made choices between actors who had disabilities and actors who were able bodied; orthopedic disability was signified by a person sitting in a wheelchair and social support by the choice of a teammate. Results showed that persons with disabilities (compared with those who were able bodied) reported a significantly higher tendency to conform and that this tendency was negatively related to reported levels of perceived social support. In the experimental study, conforming behaviors of both disabled and able-bodied actors elicited more social support than did assertive behaviors. The actors who had "disabilities" received less social support than those who were "able bodied," but the former were considered more original when they did not conform. The findings imply that individuals with orthopedic disabilities are expected to conform but, although their conforming behavior elicits social support within specific encounters, it does not affect overall social support across encounters.

Occipital condylar dysplasia in two Jacob sheep.

Two young Jacob sheep which presented with severe ataxia and torticollis had abnormally formed atlanto-occipital joints. Postmortem examination revealed marked dissimilarity in size between the left and right occipital condyles, with reduction in size of the foramen magnum. The atlantoaxial joint and dens were normally formed, and were not abnormally positioned in radiographs taken of one lamb. Histological evaluation of the cervicomedullary junction demonstrated extensive loss of axons and myelin, gliosis, and mild hydromyelia in one lamb.

Use of ultrasonography and secondary wound closure to facilitate diagnosis and treatment of a cranial mediastinal abscess in a dog.

A 3-year-old dog was examined because of acute, severe respiratory distress. Harsh inspiratory sounds, oral abrasions, and pyrexia were identified. On thoracic and cervical radiographs, the trachea appeared to be ventrally displaced and narrowed for several centimeters of its length at the thoracic inlet. Cytologic examination of a transcutaneous aspirate from the caudal cervical region revealed a neutrophilic exudate with extracellular bacteria. The ultrasonographic appearance of the thoracic inlet lent support to a diagnosis of cranial mediastinal abscess. Drainage and debridement of the abscess was accomplished via a ventral midline cervical approach, and the site was managed as an open wound. After 6 days, secondary wound closure was performed. The ventral cervical approach prevented contamination of the pleural space, and treatment as an open wound allowed inspection of the affected tissues to determine optimal time for wound closure. The cause of this cranial mediastinal abscess was unknown.

Closure of the iliac crest ossification center in dogs: 750 cases (1980-1987).

Radiographs of 750 dogs were examined to determine whether the iliac crest ossification center was open or closed. The center was closed in most dogs by 2 years of age. Eighteen percent of dogs greater than or equal to 10 years old had open iliac crest ossification center; 10% of dogs greater than or equal to 14 years old had open iliac crest ossification center. Closure of the iliac crest ossification center is extremely variable and, in many dogs, occurs at later age than has been previously reported.

Overcoming denial and increasing the intention to use condoms through the induction of hypocrisy.

Feelings of hypocrisy were induced in college students to increase condom use. Hypocrisy was created by making subjects mindful of their past failure to use condoms and then having them persuade others about the importance of condoms for AIDS prevention. The induction of hypocrisy decreased denial and led to greater intent to improve condom use relative to the control conditions. The implications of these findings for AIDS prevention are discussed.

Escherichia coli bacteremia associated with hypertrophic osteodystrophy in a dog.

Escherichia coli bacteremia was detected in a dog that had hypertrophic osteodystrophy. The dog improved after treatment with cephalothin sodium, iv fluid therapy, and cage rest. The cause of hypertrophic dystrophy has not been determined, although an infectious cause has been suggested. Dogs that are suspected of having hypertrophic osteodystrophy should be monitored closely for evidence of septicemia, and the administration of prophylactic antibiotics may be advisable.

Transposition of the great arteries in a cat.

Transposition of the great arteries, a congenital cardiac disorder, was diagnosed in a 4-month-old domestic short-haired kitten. Angiography revealed a patent ductus arteriosis, with the pulmonary artery originating from the left ventricle and the aorta originating from the right ventricle. Blood gas analysis suggested a high ventricular septal defect. Necropsy confirmed the diagnosis.

ATP-dependent calcium uptake activity associated with a disk membrane fraction isolated from bovine retinal rod outer segments.

Ca2+ sequestration and release from disks of rod outer segments may play a critical role in visual transduction. An ATP-dependent Ca2+ uptake activity has been identified in association with purified disks of bovine rod outer segments. A crude preparation of osmotically active disks was obtained from rod outer segments by hypoosmotic shock and subsequent flotation on a 5% Ficoll 400 solution. These "crude" disks were further purified by separation into two distinct components by centrifugation in a linear Ficoll gradient. Disks comprised the major component; at least 60% of the protein was rhodopsin. This fraction also contained a Ca2+ uptake activity stimulated approximately 4-fold by ATP. The initial rate was approximately 0.21 nmol of Ca2+ (mg of protein)-1 min-1. Most of the ATP-dependent accumulation of 45Ca2+ was released by the calcium ionophore A23187. The uptake activity was sensitive to vanadate (Ki approximately 20 microM) and insensitive to the mitochondrial Ca2+ uptake inhibitor ruthenium red (10 microM). The ATP-dependent Ca2+ uptake exhibited Michaelis-Menten activation kinetics with respect to [Ca2+] (Km approximately 6 microM). The osmotic properties of the sealed disk membranes were exploited to determine whether the association of Ca2+ transport activity with the disks was merely coincidental. The sedimentation properties of these disks, upon centrifugation on a second Ficoll linear density gradient, varied with the osmolarity of the gradient solution. In several separate gradient solutions of differing osmotic and ionic strengths, the Ca2+ uptake activity always comigrated with the disks. These results indicate that the ATP-dependent Ca2+ uptake activity was physically associated with sealed native disk membranes. The characteristics of the Ca2+ uptake activity suggest that it may play a major role in the regulation of cytosolic Ca2+ levels in rod cells in vivo.

Congenital cardiac disease in dogs.

Ventricular septal defect (VSD) generally occurs high in the membranous septum rather than lower in the muscular portion. The English Bulldog and Siberian Husky may be predisposed. Clinical signs include a holosystolic or crescendo-decrescendo murmur best heard low on the right side at the 3rd-4th intercostal space and, with large defects, pulmonary congestion, exercise intolerance, cyanosis and ascites. The ECG is normal unless the right ventricle is hypertrophied, which causes right axis deviation and other electrocardiographic signs of right-sided heart enlargement. Plain film thoracic radiographs reveal signs of right-sided heart enlargement but often are not diagnostic. Nonselective angiocardiography is often not useful in diagnosing VSD with a left-to-right shunt of blood. Selective angiocardiography, in which contrast medium is injected directly into the left ventricle via a catheter, is the method of choice for diagnosis of VSD. Dogs with a small VSD remain asymptomatic, but those with large defects require surgical correction with a prosthetic septal pathic or pulmonary artery band.

Congenital cardiac disease in dogs.

Aortic stenosis is a heritable cardiac anomaly most common in German Shepherds, Boxers and Newfoundlands, and less common in Pugs, English Bulldogs, Boston Terriers, Fox Terriers, Schnauzers and Bassets. Clinical signs are associated with secondary left-sided heart failure and include coughing, moist rales, exercise intolerance, arrhythmias and a weak femoral pulse. It causes an ejection-type crescendo-decrescendo, systolic murmur best heard on the left side near the elbow. The ECG may be normal or may show signs of left ventricular hypertrophy, including an axis of less than 40 degrees, a QRS complex of greater than 60 seconds in duration, R waves greater than 3 mv in amplitude, ST segment slurring or depression, or T waves of an amplitude greater than 25% of that of R waves. A LAT radiograph usually reveals an enlarged cardiac silhouette, loss of the cranial cardiac waist, and normal pulmonary vasculature, while DV projections show an elongated cardiac silhouette, rounding of the left ventricular border, and a normal descending aorta. Nonselective angiocardiography reveals poststenotic dilatation of the aorta. Treatment of severely affected dogs involves surgical correction.