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1.
Plant Direct ; 7(4): e489, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37124872

ABSTRACT

The Heat Shock Factor (HSF) transcription factor family is a central and required component of plant heat stress responses and acquired thermotolerance. The HSF family has dramatically expanded in plant lineages, often including a repertoire of 20 or more genes. Here we assess and compare the composition, heat responsiveness, and chromatin profiles of the HSF families in maize and Setaria viridis (Setaria), two model C4 panicoid grasses. Both species encode a similar number of HSFs, and examples of both conserved and variable expression responses to a heat stress event were observed between the two species. Chromatin accessibility and genome-wide DNA-binding profiles were generated to assess the chromatin of HSF family members with distinct responses to heat stress. We observed significant variability for both chromatin accessibility and promoter occupancy within similarly regulated sets of HSFs between Setaria and maize, as well as between syntenic pairs of maize HSFs retained following its most recent genome duplication event. Additionally, we observed the widespread presence of TF binding at HSF promoters in control conditions, even at HSFs that are only expressed in response to heat stress. TF-binding peaks were typically near putative HSF-binding sites in HSFs upregulated in response to heat stress, but not in stable or not expressed HSFs. These observations collectively support a complex scenario of expansion and subfunctionalization within this transcription factor family and suggest that within-family HSF transcriptional regulation is a conserved, defining feature of the family.

2.
Science ; 372(6539): 292-295, 2021 04 16.
Article in English | MEDLINE | ID: mdl-33859035

ABSTRACT

Gene-regulatory networks achieve complex mappings of inputs to outputs through mechanisms that are poorly understood. We found that in the galactose-responsive pathway in Saccharomyces cerevisiae, the decision to activate the transcription of genes encoding pathway components is controlled independently from the expression level, resulting in behavior resembling that of a mechanical dimmer switch. This was not a direct result of chromatin regulation or combinatorial control at galactose-responsive promoters; rather, this behavior was achieved by hierarchical regulation of the expression and activity of a single transcription factor. Hierarchical regulation is ubiquitous, and thus dimmer switch regulation is likely a key feature of many biological systems. Dimmer switch gene regulation may allow cells to fine-tune their responses to multi-input environments on both physiological and evolutionary time scales.


Subject(s)
DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Galactose/metabolism , Gene Expression Regulation, Fungal , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Galactokinase/genetics , Galactokinase/metabolism , Gene Regulatory Networks , Genetic Fitness , Glucose/metabolism , Metabolic Networks and Pathways/genetics , Models, Genetic , Promoter Regions, Genetic , Repressor Proteins/genetics , Repressor Proteins/metabolism , Saccharomyces cerevisiae/growth & development , Transcription, Genetic
3.
Sci Rep ; 7: 43367, 2017 03 07.
Article in English | MEDLINE | ID: mdl-28266540

ABSTRACT

We present a method by which the spectral intensity of an ultrafast laser pulse can be accumulated at selected frequencies by a controllable amount. Using a 4-f pulse shaper we modulate the phase of the frequency components of a femtosecond laser. By inducing femtosecond filamentation with the modulated pulse, we can concentrate the spectral amplitude of the pulse at various frequencies. The phase mask applied by the pulse shaper determines the frequencies for which accumulation occurs, as well as the intensity of the spectral concentration. This technique provides a way to obtain pulses with adjustable amplitude using only phase modulation and the nonlinear response of a medium. This provides a means whereby information which is encoded into spectral phase jumps may be decoded into measurable spectral intensity spikes.

4.
Nature ; 513(7517): 233-6, 2014 Sep 11.
Article in English | MEDLINE | ID: mdl-25043015

ABSTRACT

The evolution of the placenta from a non-placental ancestor causes a shift of maternal investment from pre- to post-fertilization, creating a venue for parent-offspring conflicts during pregnancy. Theory predicts that the rise of these conflicts should drive a shift from a reliance on pre-copulatory female mate choice to polyandry in conjunction with post-zygotic mechanisms of sexual selection. This hypothesis has not yet been empirically tested. Here we apply comparative methods to test a key prediction of this hypothesis, which is that the evolution of placentation is associated with reduced pre-copulatory female mate choice. We exploit a unique quality of the livebearing fish family Poeciliidae: placentas have repeatedly evolved or been lost, creating diversity among closely related lineages in the presence or absence of placentation. We show that post-zygotic maternal provisioning by means of a placenta is associated with the absence of bright coloration, courtship behaviour and exaggerated ornamental display traits in males. Furthermore, we found that males of placental species have smaller bodies and longer genitalia, which facilitate sneak or coercive mating and, hence, circumvents female choice. Moreover, we demonstrate that post-zygotic maternal provisioning correlates with superfetation, a female reproductive adaptation that may result in polyandry through the formation of temporally overlapping, mixed-paternity litters. Our results suggest that the emergence of prenatal conflict during the evolution of the placenta correlates with a suite of phenotypic and behavioural male traits that is associated with a reduced reliance on pre-copulatory female mate choice.


Subject(s)
Cyprinodontiformes/classification , Cyprinodontiformes/physiology , Phylogeny , Sexual Behavior, Animal/physiology , Viviparity, Nonmammalian/physiology , Animals , Body Size , Cyprinodontiformes/anatomy & histology , Female , Genitalia, Male/anatomy & histology , Male , Reproduction
5.
Opt Express ; 21(20): 23772-84, 2013 Oct 07.
Article in English | MEDLINE | ID: mdl-24104289

ABSTRACT

We report generation of femtosecond-laser-induced shockwaves at an air-water interface by millijoule femtosecond laser pulses. We document and discuss the main processes accompanying this phenomenon, including light emission, development of the ablation plume in the air, formation of an ablation cavity, and, subsequently, a bubble developing in water. We also discuss the possibility of remotely controlling the characteristics of laser-induced sound waves in water through linear acoustic superposition of sound waves that results from millijoule femtosecond laser-pulse interaction with an air-water interface, thus opening up the possibility of remote acoustic applications in oceanic and riverine environments.

6.
Appl Opt ; 52(20): 4792-6, 2013 Jul 10.
Article in English | MEDLINE | ID: mdl-23852190

ABSTRACT

We demonstrate that objects buried in sand (1 to 4 mm deep) may be selectively imaged according to their chemical composition through spectral analysis of the laser-induced breakdown signal. The signal is generated by loosely focused femtosecond laser pulses having energies ranging from 0.5 to 2.5 mJ. We determine the depth from which a spectral signal may be measured as a function of pulse energy. Having in mind applications to remote sensing, chemical-specific imaging of shallowly buried objects may find use in various fields ranging from space exploration to landmine detection.

7.
Opt Lett ; 37(1): 16-8, 2012 Jan 01.
Article in English | MEDLINE | ID: mdl-22212776

ABSTRACT

We demonstrate energy exchange between two filament-forming femtosecond laser beams in liquid methanol. Our results are consistent with those of previous works documenting coupling between filaments in air; in addition, we identify an unreported phenomenon in which the direction of energy exchange oscillates at increments in the relative pulse delay equal to an optical period (2.6 fs). Energy transfer from one filament to another may be used in remote sensing and spectroscopic applications utilizing femtosecond laser filaments in water and air.

8.
Mol Phylogenet Evol ; 62(1): 97-108, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22100729

ABSTRACT

Bandicoots (Peramelemorphia) are a major order of australidelphian marsupials, which despite a fossil record spanning at least the past 25 million years and a pandemic Australasian range, remain poorly understood in terms of their evolutionary relationships. Many living peramelemorphians are critically endangered, making this group an important focus for biological and conservation research. To establish a phylogenetic framework for the group, we compiled a concatenated alignment of nuclear and mitochondrial DNA sequences, comprising representatives of most living and recently extinct species. Our analysis confirmed the currently recognised deep split between Macrotis (Thylacomyidae), Chaeropus (Chaeropodidae) and all other living bandicoots (Peramelidae). The mainly New Guinean rainforest peramelids were returned as the sister clade of Australian dry-country species. The wholly New Guinean Peroryctinae was sister to Echymiperinae. The poorly known and perhaps recently extinct Seram Bandicoot (Rhynchomeles) is sister to Echymipera. Estimates of divergence times from relaxed-clock Bayesian methods suggest that living bandicoots originated in the late Oligocene or early Miocene, much earlier than currently thought based on fossils. Subsequent radiations within Peramelemorphia probably took place on the Australian mainland during the Miocene, with diversification of rainforest taxa on the newly emergent New Guinean landmasses through the middle-late Miocene and complete establishment of modern lineages by the early Pliocene.


Subject(s)
DNA, Mitochondrial/genetics , Genetic Speciation , Marsupialia/genetics , Animals , Australia , Bayes Theorem , Endangered Species , Evolution, Molecular , Extinction, Biological , Genes, BRCA1 , Homeodomain Proteins/genetics , INDEL Mutation , Likelihood Functions , Marsupialia/classification , New Guinea , Phylogeny , Phylogeography , Sequence Analysis, DNA
9.
Diabetes Obes Metab ; 13(6): 498-504, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21272190

ABSTRACT

AIM: We examined the effects of the 11ß-hydroxysteroid dehydrogenase type 1 (HSD1) inhibitor, MK-0916, on the multiple components of the metabolic syndrome (MetS) in patients with type 2 diabetes (T2DM) and MetS. METHODS: This was a 12-week, multicentre, randomized, double-blind, placebo-controlled study. Patients with T2DM (mean baseline A1C: 7.3%) and National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III)-defined MetS were randomized 1 : 1 : 1 : 1 to 0.5, 2 or 6 mg/day MK-0916 or placebo. The primary efficacy endpoint was a change from baseline at week 12 in fasting plasma glucose (FPG). Secondary endpoints included glycosylated haemoglobin A(1c) (A1C), 2-h postprandial glucose (2-h PPG), body weight, waist circumference, blood pressure and lipid profile. RESULTS: Treatment with MK-0916 had no significant effect relative to placebo on FPG at week 12. Compared to placebo, 6 mg MK-0916 produced a modest, significant (p = 0.049) reduction in A1C of 0.3% at week 12, but no significant difference was observed in 2-h PPG. Six milligram MK-0916 increased LDL-C relative to placebo by 10.4% (p = 0.041). Treatment with MK-0916 led to modest dose-dependent decreases in blood pressure and body weight. Overall, MK-0916 was generally well tolerated. MK-0916 produced mechanism-based activation of the hypothalamic-pituitary-adrenal axis, resulting in mean increases in adrenal androgen levels that remained within the normal range at all doses tested. CONCLUSIONS: Inhibition of HSD1 with MK-0916 was generally well tolerated in patients with T2DM and MetS. Although no significant improvement in FPG was observed with MK-0916 compared to placebo, modest improvements in A1C, body weight and blood pressure were observed.


Subject(s)
11-beta-Hydroxysteroid Dehydrogenase Type 1/antagonists & inhibitors , 11-beta-Hydroxysteroid Dehydrogenase Type 1/pharmacology , Blood Glucose/drug effects , Diabetes Mellitus, Type 2/drug therapy , Glycated Hemoglobin/drug effects , Metabolic Syndrome/drug therapy , Adolescent , Adult , Aged , Analysis of Variance , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/physiopathology , Female , Glycated Hemoglobin/metabolism , Humans , Male , Metabolic Syndrome/metabolism , Metabolic Syndrome/physiopathology , Middle Aged , Placebos , Postprandial Period , Young Adult
10.
Health SA Gesondheid (Print) ; 15(1): 1-8, 2010.
Article in English | AIM (Africa) | ID: biblio-1262456

ABSTRACT

According to existing literature; ancillary health care workers (AHCWs) often do not meet the health care needs of patients with physical disabilities (physically disabled patients) in a home-based environment; because of inadequate training programmes. The purpose of this research study was to explore the health care needs of physically disabled patients in long-term; home-based care in the northern suburbs of Johannesburg and; based on results; to offer recommendations for the training of AHCWs. Qualitative; exploratory; descriptive and contextual means were employed in data collection and analysis. The population consisted of eight physically disabled participants who employed an AHCW to assist them with their long-term home care. Purposive sampling was used with subsequent snowballing to identify further participants for the study. Individual interviews were conducted; where participants had to answer the questions (1)'What are your health care needs?' and (2) 'How should these be met?' Data saturation was ensured; after which Tesch's method of data analysis was followed. Three categories of health care needs were identified (1) physical health care needs; (2) interpersonal relationship needs and (3) social needs; and 12 themes were derived from these categories. These categories of health care needs should be addressed in the training of AHCWs. From the themes; recommendations were described for the training of AHCWs on the health care needs of the home-based physically disabled patients. The AHCW should assist in the adaptation of the environment to the patient's individual needs; and should use knowledge and critical thinking skills to ensure a patient-centred care setting


Subject(s)
Disabled Persons , Health Services Needs and Demand , Home Care Services/education
11.
Rev. biol. trop ; 57(supl.1): 275-284, nov. 2009. ilus, graf, tab
Article in Spanish | LILACS, SaludCR | ID: lil-637941

ABSTRACT

Benthic macroinvertebrates of the Palo Verde wetland, Costa Rica. Palo Verde, Costa Rica, is one of the most important wetlands in the region now recovering from some invasive plants, especially Typha domingensis, and monitoring programs were started, including studies on the aquatic macoinvertebrate fauna. We sampled benthic macroinvertebrates monthly for more than a year with artificial substrates, and identified 116 taxa from 57 families and 18 orders, with 90 morfospecies of insects. The highest abundances were in the class Conchostraca (typical in seasonal wetlands) and in the family Chironomidae (Diptera, Insecta), which together represent almost half of all individuals collected. In contrast, 97 taxa were less than 1% of total abundance each. Number of individuals and number of species were higher at lower water levels (dry season). Cumulative species curves indicate that more species would be found if sampling had continued for more time. Rev. Biol. Trop. 57 (Suppl. 1): 275-284. Epub 2009 November 30.


El humedal de Palo Verde es uno de los más importantes de Centro America para aves acuáticas. Durante el período 2002 y 2005, se llevaron a cabo actividades de manejo para controlar la invasión de Typha domingensis. Con el fin de establecer una línea base para monitoreos futuros, en el 2003 se realizó una evaluación de macroinvertebrados acuáticos. Se efectuó un muestreo mensual durante un año, usando el método de sustratos artificiales. Se identificaron 116 táxones pertenecientes a 47 familias y a 18 órdenes. La mayor abundancia se encontró en la clase Conchostraca y la familia Chironomidae que juntas representaron casi la mitad de todos los individuos colectados. En contraste, el 97% de los táxones tuvieron, cada uno, menos del 1% del total de la abundancia. La diversidad de táxones, así como la abundancia de individuos y el número de especies, fueron mayores en la época seca que en la lluviosa. La curva acumulada de especies indicó que se hubiera registrado una mayor cantidad de táxones si los muestreos se hubieran extendido por más tiempo. Con este trabajo damos a conocer la primera lista de macroinvertebrados para el humedal de Palo Verde.


Subject(s)
Benthic Fauna , Classification , Wetlands , Invertebrates/classification , Costa Rica
12.
Clin Pharmacol Ther ; 83(4): 551-8, 2008 Apr.
Article in English | MEDLINE | ID: mdl-17957186

ABSTRACT

The pharmacokinetics of zolpidem was assessed in this open-label, dose-escalation study in children with insomnia. Twenty-one children, seven per age group (2-6, >6 to 12, >12 to 18 years), received a single dose of zolpidem at one of the three dose levels (0.125, 0.25, or 0.50 mg/kg (20 mg maximum dose)). Multiple pharmacokinetic measures were assessed at nine post-dose intervals and pharmacodynamics was assessed by polysomnography and actigraphy. Significant pharmacokinetic effects by dose were observed only as linear increases in maximum concentration (C(max), P<0.001) and area under the plasma concentration-time curve (AUC, P<0.001). Significant pharmacokinetic effects by age group included an increase in AUC (P=0.02), half-life (P=0.04), and mean residence time (P=0.01), whereas total body clearance decreased (P=0.01) and steady-state volume of distribution was variable. Pharmacodynamic measures were independent of the pharmacokinetic estimates. Overall, zolpidem was well tolerated and a pediatric dose of 0.25 mg/kg is recommended for future efficacy studies.


Subject(s)
Hypnotics and Sedatives/administration & dosage , Hypnotics and Sedatives/pharmacokinetics , Pyridines/administration & dosage , Pyridines/pharmacokinetics , Sleep Initiation and Maintenance Disorders/drug therapy , Adolescent , Age Factors , Analysis of Variance , Area Under Curve , Child , Child, Preschool , Drug Administration Schedule , Female , Humans , Hypnotics and Sedatives/adverse effects , Male , Pyridines/adverse effects , Zolpidem
13.
J Biomed Mater Res A ; 86(3): 788-95, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18041723

ABSTRACT

This study investigated the combined application of Transforming Growth Factor beta-1 (TGFbeta-1) and Bone Morphogenetic Protein-2 (BMP-2) to stimulate osteogenic expression in vitro. TGFbeta-1 and BMP-2 fulfill specific roles in the formation of new bone. COLLOSS E, a bone-derived collagen product containing a variety of naturally occurring growth factors, was also used. Growth factors were administered to osteoblast-like cells from rat bone marrow (RBM). Proliferation and differentiation were monitored up to 24 days, by measuring total DNA content, alkaline phosphatase activity, and calcium content. Genetic expression of a set of differentiation markers at day 7 was measured by Q-PCR. Adding BMP-2 alone induced high proliferation rates, compared to the growth factor supplemented groups, and it induced high differentiation rates, compared to the control group. Adding TGFbeta-1 combined with BMP-2, TGFbeta-1 alone, or COLLOSS E resulted in a significant decrease in proliferation rate, but an increase in differentiation rate, compared to the control group. Additive or synergistic effects of application of TGFbeta-1 and BMP-2 were not observed. The observed effects of COLLOSS E mainly resembled those of TGFbeta-1 application alone. It can be concluded that BMP-2 is the most suitable candidate for osteogenic stimulation of RBM cells in these settings.


Subject(s)
Bone Marrow Cells/cytology , Bone Morphogenetic Proteins/pharmacology , Collagen/pharmacology , Osteoblasts/cytology , Osteoblasts/drug effects , Transforming Growth Factor beta1/pharmacology , Transforming Growth Factor beta/pharmacology , Alkaline Phosphatase/genetics , Alkaline Phosphatase/metabolism , Animals , Bone Marrow Cells/enzymology , Bone Morphogenetic Protein 2 , Calcium/metabolism , Cell Proliferation/drug effects , DNA/biosynthesis , Gene Expression Regulation/drug effects , Male , Osteoblasts/enzymology , Osteoblasts/ultrastructure , Rats , Rats, Wistar , Reverse Transcriptase Polymerase Chain Reaction
14.
Nucleic Acids Res ; 35(9): 3016-31, 2007.
Article in English | MEDLINE | ID: mdl-17439971

ABSTRACT

Ribosomal protein L20 is crucial for the assembly of the large ribosomal subunit and represses the translation of its own mRNA. L20 mRNA carries two L20-binding sites, the first folding into a pseudoknot and the second into an imperfect stem and loop. These two sites and the L20-binding site on 23S ribosomal RNA are recognized similarly using a single RNA-binding site located on one face of L20. In this work, using gel filtration and fluorescence cross-correlation spectroscopy (FCCS) experiments, we first exclude the possibility that L20 forms a dimer, which would allow each monomer to bind one site of the mRNA. Secondly we show, using affinity purification and FCCS experiments, that only one molecule of L20 binds to the L20 mRNA despite the presence of two potential binding sites. Thirdly, using RNA chemical probing, we show that the two L20-binding sites are in interaction. This interaction provides an explanation for the single occupancy of the mRNA. The two interacting sites could form a single hybrid site or the binding of L20 to a first site may inhibit binding to the second. Models of regulation compatible with our data are discussed.


Subject(s)
Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , RNA, Messenger/chemistry , Ribosomal Proteins/genetics , Ribosomal Proteins/metabolism , Base Sequence , Binding Sites , Chromatography, Affinity , Chromatography, Gel , Escherichia coli Proteins/chemistry , Molecular Sequence Data , Nucleic Acid Conformation , Operator Regions, Genetic , Protein Binding , Protein Structure, Quaternary , RNA, Messenger/metabolism , Ribosomal Proteins/chemistry , Spectrometry, Fluorescence
15.
Neuropsychologia ; 45(7): 1438-51, 2007 Apr 08.
Article in English | MEDLINE | ID: mdl-17204295

ABSTRACT

Adults' expertise in recognizing facial identity involves encoding subtle differences among faces in the shape of individual facial features (featural processing) and in the spacing among features (a type of configural processing called sensitivity to second-order relations). We used fMRI to investigate the neural mechanisms that differentiate these two types of processing. Participants made same/different judgments about pairs of faces that differed only in the shape of the eyes and mouth, with minimal differences in spacing (featural blocks), or pairs of faces that had identical features but differed in the positions of those features (spacing blocks). From a localizer scan with faces, objects, and houses, we identified regions with comparatively more activity for faces, including the fusiform face area (FFA) in the right fusiform gyrus, other extrastriate regions, and prefrontal cortices. Contrasts between the featural and spacing conditions revealed distributed patterns of activity differentiating the two conditions. A region of the right fusiform gyrus (near but not overlapping the localized FFA) showed greater activity during the spacing task, along with multiple areas of right frontal cortex, whereas left prefrontal activity increased for featural processing. These patterns of activity were not related to differences in performance between the two tasks. The results indicate that the processing of facial features is distinct from the processing of second-order relations in faces, and that these functions are mediated by separate and lateralized networks involving the right fusiform gyrus, although the FFA as defined from a localizer scan is not differentially involved.


Subject(s)
Brain Mapping , Brain/physiology , Discrimination, Psychological/physiology , Face , Pattern Recognition, Visual/physiology , Adolescent , Adult , Brain/blood supply , Facial Expression , Female , Functional Laterality , Humans , Image Processing, Computer-Assisted/methods , Male , Oxygen/blood , Photic Stimulation/methods , Space Perception
16.
Mol Phylogenet Evol ; 31(2): 476-85, 2004 May.
Article in English | MEDLINE | ID: mdl-15062789

ABSTRACT

Complete 12S rRNA and partial cytochrome b (cytb) gene sequences have been obtained from museum samples of two recently extinct potoroids-Potorous platyops and Caloprymnus campestris. Phylogenetic analyses based on these mitochondrial DNA sequences suggest that the broad-faced potoroo (P. platyops) was a close relative of the recently discovered Potorous longipes and the recently re-discovered Potorous gilberti. Although the extinct desert rat-kangaroo (C. campestris) was clearly resolved as a member of the subfamily Potoroinae, its precise relationships vis a vis other living potoroines are unclear. We confirmed that the rufous rat-kangaroo (Aepyprymnus rufescens) is sister to all living Bettongia species, but the molecular data provide no support for a sister relationship between A. rufescens and C. campestris as suggested by on the basis of four shared morphological characters. Molecular dating analyses suggest that the initial radiation of potoroinae seems to have occurred soon after its origin in the early Miocene. Within Potoroinae, C. campestris diverged from other taxa approximately 16 million years ago. P. platyops diverged from P. longipes+P. gilberti approximately 14-15 million years ago.


Subject(s)
Cytochromes b/genetics , Marsupialia/classification , Marsupialia/genetics , Phylogeny , RNA, Ribosomal/genetics , Animals , Sequence Analysis, DNA
17.
J Clin Pharmacol ; 43(11): 1196-202, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14551173

ABSTRACT

This article examines the feasibility, effectiveness, and ethical constraints relevant to appropriate financial compensation of the pediatric house officer who functions as a research-subject locator (RSL). When carefully trained and supervised, the RSL can facilitate timely enrollment of research subjects in pediatric drug trials, augment the house officer training experience, and advocate for children to increase therapeutic options available for pediatric care. When monitored within the clinical trial schema, the RSL has no direct link to the study outcome and thus performs within ethical standards for subject enrollment and study participation.


Subject(s)
Clinical Trials as Topic/methods , Internship and Residency/methods , Patient Selection , Child , Clinical Trials as Topic/economics , Clinical Trials as Topic/ethics , Humans , Internship and Residency/economics , Internship and Residency/ethics , Patient Selection/ethics
18.
J Anim Sci ; 81(6): 1464-72, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12817494

ABSTRACT

Our objectives were to determine the optimal accelerated chill time immediately postmortem necessary to improve the quality of pork muscle and to decrease the incidence of pale, soft, and exudative pork. Carcasses from 81 market hogs were cooled either by conventional chill (CC) at 2 degrees C or by accelerated chill (AC) at -32 degrees C for 60, 90, 120, or 150 min, and then placed into a 2 degrees C cooler for the remainder of the 24-h chill period. Loin muscle pH was higher (P < 0.05) for the carcasses that were accelerated chilled longer than 60 min. Although loin visual color, texture, and firmness scores increased (P < 0.05) with AC time, no improvements were noted beyond 60 min. Color, pH, texture, firmness, and CIE L*a*b* values of fresh ham muscles were not (P > 0.05) affected by AC. In addition, AC did not (P > 0.05) affect purge, drip, or thaw loss of fresh products, sensory scores of loins or processed hams (except initial juiciness; P < 0.05), water-holding capacity of processed hams, or processing characteristics of hams. Cooking loss and Warner-Bratzler shear values for hams and loins were not (P > 0.05) affected by AC. Accelerated chilling caused loins to be darker (lower L* value; P < 0.05) and to have lower (P < 0.05) b* values (less yellow) than CC loins. Accelerated chilling increased water-holding capacity in fresh hams, bound water being the greatest (P < 0.05) in the 120- and 150-min AC groups. These results demonstrate that improvements in pork loin quality can be made using freezer-accelerated chilling for carcasses.


Subject(s)
Food Handling/methods , Freezing , Meat/standards , Animals , Color , Hydrogen-Ion Concentration , Male , Quality Control , Swine , Time Factors
19.
Fam Pract ; 20(2): 142-6, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12651787

ABSTRACT

BACKGROUND: Pre-conception counselling has the potential to reduce pregnancy complications and congenital disorders. The timing of counselling, before conception, is crucial to maximize the benefit. As many couples are unaware of their risk status and the fact that the first period of pregnancy is crucial, they do not seek information before pregnancy occurs. To reach couples with timely information, it seems that a health care worker needs to take the initiative. In The Netherlands, the GP is in an ideal position to offer pre-conception counselling. OBJECTIVE: The aim of this study was to determine the interest of women aged 18-40 in pre-conception counselling if this is offered to them by their own GP. METHOD: A cohort of women (n = 1206) received a personal letter from their own GP with an offer of pre-conception counselling. The women were requested to fill in a reply form, indicating if they were interested, might be interested (if they decided to become pregnant) or were not interested in an invitation for pre-conception counselling. When interested, they were asked to give an indication as to when they were planning a pregnancy. Women who were not interested were requested to give a reason. RESULTS: Almost 70% of the women returned the reply form. Up to the age of 29 years, at least 80% of the respondents were interested or might be interested should they decide to have children. Most women, especially the younger women, do not know exactly when they wish to become pregnant. Regardless of age, >70% of the respondents were interested. Only 11% of the respondents indicated specifically that they were not interested in advice. CONCLUSION: Women are interested in GP-initiated pre-conception counselling. Further research is needed to assess the effect of programmed and systematic pre-conception counselling, offered by GPs, on pregnancy outcome and the health of the children. A randomized controlled trial to assess these effects currently is being conducted at the Department of General Practice in Leiden.


Subject(s)
Counseling , Family Practice , Preconception Care/methods , Adolescent , Adult , Congenital Abnormalities/prevention & control , Family Planning Services , Female , Humans , Netherlands , Pregnancy , Pregnancy Complications/prevention & control
20.
Ned Tijdschr Geneeskd ; 146(45): 2132-4, 2002 Nov 09.
Article in Dutch | MEDLINE | ID: mdl-12474552

ABSTRACT

With the publication of the Dutch College of General Practitioners' practice guideline 'Examination of the neonate', a discussion which has lasted several decades has been brought to an end. Up to now a second neonatal examination by the general practitioner on the third, fourth or fifth day after a midwife-assisted birth was recommended. The arguments in support of this recommendation were based on the following: (a) the limited expertise of midwives in the past, (b) the experience that general practitioners had in examining children, although this experience was not specifically related to the defects for which neonates should be checked, and (c) the government bodies' wish to restrict the number of hospital deliveries by giving greater structure to the organisation of midwife care, which in practice, did not lead to large changes. Based on three studies, the practice guideline recommends that a second examination is of no added value.


Subject(s)
Neonatal Screening/standards , Practice Guidelines as Topic , Practice Patterns, Physicians' , Clinical Competence , Family Practice , Humans , Infant, Newborn , Midwifery , Netherlands , Physical Examination
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