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1.
Heliyon ; 9(11): e21428, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37954353

ABSTRACT

The United Nations Sustainable Development Goals aim to double the productivity of small-medium food producers (2015-2030), while food demand is estimated to increase by 60 % by 2050. The objectives of this paper were to identify and quantify the relationship between energy efficiency and milking efficiency, identify the main energy consuming processes associated with milking, and investigate whether milking efficiency, energy efficiency or the relationship between them varies depending on parlour type. Energy and milking efficiency data from 26 pasture-based dairy farms in the Republic of Ireland were analysed (17 herringbone, nine rotary). Energy consumption was monitored continuously on the herringbone farms and for two distinct, seven-day periods (observation periods 1 and 2) for the rotary farms. Milking performance was monitored for all 26 farms during these periods. During the observation periods, the rotary farms achieved superior energy efficiency (29.85 Wh kgMilk-1) and milking efficiency (152 cows/hour) than the herringbone farms (32.83 Wh kgMilk-1, 97 cows/hour). Moderate correlations existed between milking efficiency (cows/hour) and energy efficiency (Wh kgMilk-1) for rotary (r = -0.58, R2 = 0.34) and herringbone (r = -0.44, R2 = 0.19). These results indicated that higher levels of milking efficiency were moderately correlated with improved energy efficiency.

2.
Front Neurosci ; 17: 1151309, 2023.
Article in English | MEDLINE | ID: mdl-37332854

ABSTRACT

Introduction: Sensorimotor integration is critical for generating skilled, volitional movements. While stroke tends to impact motor function, there are also often associated sensory deficits that contribute to overall behavioral deficits. Because many of the cortico-cortical projections participating in the generation of volitional movement either target or pass-through primary motor cortex (in rats, caudal forelimb area; CFA), any damage to CFA can lead to a subsequent disruption in information flow. As a result, the loss of sensory feedback is thought to contribute to motor dysfunction even when sensory areas are spared from injury. Previous research has suggested that the restoration of sensorimotor integration through reorganization or de novo neuronal connections is important for restoring function. Our goal was to determine if there was crosstalk between sensorimotor cortical areas with recovery from a primary motor cortex injury. First, we investigated if peripheral sensory stimulation would evoke responses in the rostral forelimb area (RFA), a rodent homologue to premotor cortex. We then sought to identify whether intracortical microstimulation-evoked activity in RFA would reciprocally modify the sensory response. Methods: We used seven rats with an ischemic lesion of CFA. Four weeks after injury, the rats' forepaw was mechanically stimulated under anesthesia and neural activity was recorded in the cortex. In a subset of trials, a small intracortical stimulation pulse was delivered in RFA either individually or paired with peripheral sensory stimulation. Results: Our results point to post-ischemic connectivity between premotor and sensory cortex that may be related to functional recovery. Premotor recruitment during the sensory response was seen with a peak in spiking within RFA after the peripheral solenoid stimulation despite the damage to CFA. Furthermore, stimulation in RFA modulated and disrupted the sensory response in sensory cortex. Discussion: The presence of a sensory response in RFA and the sensitivity of S1 to modulation by intracortical stimulation provides additional evidence for functional connectivity between premotor and somatosensory cortex. The strength of the modulatory effect may be related to the extent of the injury and the subsequent reshaping of cortical connections in response to network disruption.

3.
J Dairy Sci ; 106(7): 4759-4772, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37268567

ABSTRACT

The increased average Irish dairy herd size in a post-quota environment has put heightened pressure on grazing infrastructure. In a rotational grazing system, grazing infrastructure consists of the paddock system, which delineates the grazing areas into appropriately sized grazing parcels, and the roadway network, which connects these paddocks to the milking parlor. Where herd size has increased without corresponding adaptations to the infrastructure, farm management and roadway network performance has been affected. The links between suboptimal grazing infrastructure and roadway network efficiency are poorly understood and not widely documented. The aims of this study were to (1) analyze the effect of herd expansion and paddock size on pasture allocations per paddock, (2) identify the factors that affect the total distance walked per year, and (3) create a metric to compare the efficiency of roadway networks across farms of varying grazing platforms. A sample population of 135 Irish dairy farms with a median herd size of 150 cows was used for this analysis. Herds were split into the following 5 categories: <100 cows, 100 to 149 cows, 150 to 199 cows, 200 to 249 cows, and ≥250 cows. Herds with ≥250 cows had a greater number of paddocks per farm and rotated around the grazing paddocks more frequently, with 46% of paddocks only suitable for 12 h allocations relative to herd size, compared with just 10% to 27% of paddocks for herds with <100 cows to herds with 200-249 cows. When predicting the total distance walked per year on each study farm, the mean distance from a paddock to the milking parlor was the strongest indicator (R2 = 0.8247). Other metrics, such as herd size, have failed to account for the location of the milking parlor relative to the grazing platform. The creation of the relative mean distance from a paddock to milking parlor (RMDMP) metric allowed the calculation of a farm's roadway network efficiency for moving the herd between paddocks and the milking parlor. The analyzed farms increased their efficiency in terms of RMDMP (0.34-40.74%) as they increased herd size post quota. However, the position of new additional paddocks relative to the milking parlor substantially affected their RMDMP.


Subject(s)
Dairying , Milk , Female , Cattle , Animals , Farms , Walking , Adaptation, Physiological , Lactation
4.
bioRxiv ; 2023 Jan 20.
Article in English | MEDLINE | ID: mdl-36711682

ABSTRACT

Sensorimotor integration is critical for generating skilled, volitional movements. While stroke tends to impact motor function, there are also often associated sensory deficits that contribute to overall behavioral deficits. Because many of the cortico-cortical projections participating in the generation of volitional movement either target or pass-through primary motor cortex (in rats, caudal forelimb area; CFA), any damage to CFA can lead to a subsequent disruption in information flow. As a result, the loss of sensory feedback is thought to contribute to motor dysfunction even when sensory areas are spared from injury. Previous research has suggested that the restoration of sensorimotor integration through reorganization or de novo neuronal connections is important for restoring function. Our goal was to determine if there was crosstalk between sensorimotor cortical areas with recovery from a primary motor cortex injury. First, we investigated if peripheral sensory stimulation would evoke responses in the rostral forelimb area (RFA), a rodent homologue to premotor cortex. We then sought to identify whether intracortical microstimulation-evoked activity in RFA would reciprocally modify the sensory response. We used seven rats with an ischemic lesion of CFA. Four weeks after injury, the rats' forepaw was mechanically stimulated under anesthesia and neural activity was recorded in the cortex. In a subset of trials, a small intracortical stimulation pulse was delivered in RFA either individually or paired with peripheral sensory stimulation. Our results point to post-ischemic connectivity between premotor and sensory cortex that may be related to functional recovery. Premotor recruitment during the sensory response was seen with a peak in spiking within RFA after the peripheral solenoid stimulation despite the damage to CFA. Furthermore, stimulation evoked activity in RFA modulated and disrupted the sensory response in sensory cortex, providing additional evidence for the transmission of premotor activity to sensory cortex and the sensitivity of sensory cortex to premotor cortex's influence. The strength of the modulatory effect may be related to the extent of the injury and the subsequent reshaping of cortical connections in response to network disruption.

5.
J Dairy Sci ; 97(6): 3352-63, 2014.
Article in English | MEDLINE | ID: mdl-24731634

ABSTRACT

The objective of this study was to assess the suitability of 3 different modeling techniques for the prediction of total daily herd milk yield from a herd of 140 lactating pasture-based dairy cows over varying forecast horizons. A nonlinear auto-regressive model with exogenous input, a static artificial neural network, and a multiple linear regression model were developed using 3 yr of historical milk-production data. The models predicted the total daily herd milk yield over a full season using a 305-d forecast horizon and 50-, 30-, and 10-d moving piecewise horizons to test the accuracy of the models over long- and short-term periods. All 3 models predicted the daily production levels for a full lactation of 305 d with a percentage root mean square error (RMSE) of ≤ 12.03%. However, the nonlinear auto-regressive model with exogenous input was capable of increasing its prediction accuracy as the horizon was shortened from 305 to 50, 30, and 10 d [RMSE (%)=8.59, 8.1, 6.77, 5.84], whereas the static artificial neural network [RMSE (%)=12.03, 12.15, 11.74, 10.7] and the multiple linear regression model [RMSE (%)=10.62, 10.68, 10.62, 10.54] were not able to reduce their forecast error over the same horizons to the same extent. For this particular application the nonlinear auto-regressive model with exogenous input can be presented as a more accurate alternative to conventional regression modeling techniques, especially for short-term milk-yield predictions.


Subject(s)
Linear Models , Milk/metabolism , Neural Networks, Computer , Animals , Cattle , Dairying , Female , Lactation
6.
Clin Pharmacol Ther ; 87(6): 668-71, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20130570

ABSTRACT

The incidence of cough in children receiving antihypertension therapy with angiotensin-converting enzyme inhibitors (ACEis) or angiotensin receptor blockers (ARBs) is unknown. We analyzed patient-level data from eight randomized trials for the treatment of pediatric hypertension, six of them involving ACEis and two involving ARBs. The incidence of cough in children receiving ACEis (reported cough, 3.2%) was similar to that in children receiving ARBs (reported cough, 1.8%) (P = 0.34). Reports of cough were lower in children than in adults.


Subject(s)
Angiotensin II Type 1 Receptor Blockers/adverse effects , Angiotensin-Converting Enzyme Inhibitors/adverse effects , Cough/chemically induced , Hypertension/drug therapy , Adolescent , Adult , Angiotensin II Type 1 Receptor Blockers/therapeutic use , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Child , Cough/epidemiology , Female , Humans , Incidence , Male , Prevalence , Randomized Controlled Trials as Topic
7.
J Med Entomol ; 46(4): 866-72, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19645291

ABSTRACT

Vesicular stomatitis New Jersey virus (VSNJV) is an insect-transmitted Rhabdovirus causing vesicular disease in domestic livestock including cattle, horses, and pigs. Natural transmission during epidemics remains poorly understood, particularly in cattle, one of the most affected species during outbreaks. This study reports the first successful transmission of VSNJV to cattle by insect bite resulting in clinical disease. When infected black flies (Simulium vittatum Zetterstedt) fed at sites where VS lesions are usually observed (mouth, nostrils, and foot coronary band), infection occurred, characterized by local viral replication, vesicular lesions, and high neutralizing antibody titers (> 1: 256). Viral RNA was detected up to 9 d postinfection in tissues collected during necropsy from lesion sites and lymph nodes draining those sites. Interestingly, when flies were allowed to feed on flank or neck skin, viral replication was poor, lesions were not observed, and low levels of neutralizing antibodies (range, 1:8-1:32) developed. Viremia was never observed in any of the animals and infectious virus was not recovered from tissues on necropsies performed between 8 and 27 d postinfection. Demonstration that VSNJV transmission to cattle by infected black flies can result in clinical disease contributes to a better understanding of the epidemiology and potential prevention and control methods for this important disease.


Subject(s)
Insect Bites and Stings/veterinary , Simuliidae/virology , Vesicular Stomatitis/transmission , Vesicular stomatitis New Jersey virus/isolation & purification , Animals , Cattle , Feeding Behavior , Female , Insect Bites and Stings/virology , Simuliidae/physiology , Vesicular Stomatitis/prevention & control , Vesicular Stomatitis/virology , Vesicular stomatitis New Jersey virus/immunology
8.
Clin Pharmacol Ther ; 84(3): 315-9, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18548000

ABSTRACT

Angiotensin-converting enzyme (ACE) inhibitors are frequently used to treat hypertension in children.(1) ACE inhibitors alter the balance between the vasoconstrictive, salt-retentive, and cardiac hypertrophic properties of angiotensin II and the vasodilatory and natriuretic properties of bradykinin; they also alter the metabolism of other vasoactive substances.(2) Through these mechanisms, ACE inhibitors decrease systemic vascular resistance and promote natriuresis without increasing heart rate. This study evaluated the results of six trials of ACE inhibitors in children, using meta-analytic techniques to estimate the effect of race on blood pressure response.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors/pharmacology , Antihypertensive Agents/pharmacology , Black People , Blood Pressure/drug effects , White People , Adolescent , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Antihypertensive Agents/therapeutic use , Child , Female , Humans , Hypertension/drug therapy , Male , Randomized Controlled Trials as Topic
9.
Vet Pathol ; 43(6): 943-55, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17099151

ABSTRACT

Horses were inoculated with Vesicular stomatitis New Jersey and Indiana viruses by routes simulating contact and vector transmission. Clinical signs, lesions, antibody development, viral shedding and persistence, and viremia were monitored. Horses were infected with both viruses by all routes as confirmed by seroconversion. Salivation, primary lesions at inoculation sites, and secondary oral lesions were the most common clinical findings. Viral shedding was most often from the oral cavity, followed by the nasal cavity; titers were highest from oral cavity samples. Virus was rarely isolated from the conjunctival sac and never from feces or blood. Development of neutralizing antibody coincided with cessation of lesion development and detection of virus by isolation. Circulating virus-specific IgM, IgG, IgA, and neutralizing antibodies developed in most animals postinoculation (PI) days 6 to 12, depending on the route of inoculation. At postmortem (PI days 12 to 15), lesions were healing, were not vesicular, and did not contain detectable virus by isolation, reverse transcriptase polymerase chain reaction, or immunohistochemistry. Numerous infiltrating lymphocytes and plasma cells suggested that lesion resolution was partially due to local immunity. Detection of viral RNA from tonsil and lymph nodes of head at necropsy suggests that these tissues play a role in the pathogenesis of the disease; molecular techniques targeting these tissues may be useful for confirming infection in resolving stages of disease. The routes of inoculation used in this study reflect the diversity of transmission routes that may occur during outbreaks and can be used to further study contact and vector transmission, vaccine development, and clarify pathogenesis of the disease in horses.


Subject(s)
Horse Diseases/virology , Rhabdoviridae Infections/veterinary , Stomatitis/veterinary , Vesicular stomatitis Indiana virus/isolation & purification , Vesiculovirus , Animals , Antibodies, Viral/blood , Female , Horses , Immunoglobulin A/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Male , Mouth/pathology , Mouth/virology , Rhabdoviridae Infections/virology , Stomatitis/virology , Virus Shedding
10.
J Vet Diagn Invest ; 14(1): 73-6, 2002 Jan.
Article in English | MEDLINE | ID: mdl-12680651

ABSTRACT

Clinical, gross, and microscopic pathologic and immunohistochemical findings in pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV) suggest that PRRSV may replicate in endothelial cells. Endothelial cell cultures from porcine aorta and pulmonary artery were tested for susceptibility to various strains of PRRSV. Cultures were identified as endothelium by light microscopy and immunohistochemical staining for P-selectin and von Willebrand factor. Five strains of PRRSV, i.e., the National Veterinary Services Laboratories, Ames, IA PRRSV strain 130-PDV and 4 field strains isolated from pneumonic lungs, failed to replicate in these porcine large-vessel endothelial cell cultures.


Subject(s)
Endothelium, Vascular/cytology , Endothelium, Vascular/virology , Porcine respiratory and reproductive syndrome virus/physiology , Swine , Virus Replication , Animals , Aorta/cytology , Cell Culture Techniques , Pulmonary Artery/cytology
11.
Psychol Aging ; 16(3): 532-49, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11554529

ABSTRACT

Several theories have suggested that age-related declines in cognitive processing are due to a pervasive unitary mechanism, such as a decline in processing speed. Structural equation model tests have shown some support for such common factor explanations. These results, however, may not be as conclusive as previously claimed. A further analysis of 4 cross-sectional data sets described in Salthouse, Hambrick, and McGuthry (1998) and Salthouse and Czaja (2000) found that although the best fitting model included a common factor in 3 of the data sets, additional direct age paths were significant, indicating the presence of specific age effects. For the remaining data set, a factor-specific model fit at least as well as the best fitting common factor model. Three simulated data sets with known structure were then tested with a sequence of structural equation models. Common factor models could not always be falsified--even when they were false. In contrast, factor-specific models were more easily falsified when the true model included a unitary common factor. These results suggest that it is premature to conclude that all age-related cognitive declines are due to a single mechanism. Common factor models may be particularly difficult to falsify with current analytic procedures.


Subject(s)
Aging/psychology , Neuropsychological Tests/statistics & numerical data , Adolescent , Adult , Aged , Aged, 80 and over , Factor Analysis, Statistical , Female , Humans , Male , Middle Aged , Models, Statistical , Psychometrics , Reference Standards , Reproducibility of Results
12.
Mem Cognit ; 29(3): 478-83, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11407424

ABSTRACT

We built Deese (1959)/Roediger and McDermott (1995) (DRM) false memory lists composed of multiplication problems rather than words. Half these lists contained table-related, near neighbors (e.g., 3 x 7 = ??, 3 x 9 = ??) of a missing multiplication answer lure (e.g., 24). The other half contained problems unrelated to the lure (e.g., 5 x 5 = ??, 11 x 3 = ??). Participants solved each problem in a single list and then took immediate recognition (Experiment 1) or recall and then recognition tests (Experiment 2) for the answers. Many people misremembered that the lure was an answer to a study-phase problem, but only when solving the study list that contained the lure's neighbors. False memory was also greater for some list-lure combinations than others, as seen previously with words. We have thus demonstrated that numbers can also produce false memory, and we use the mental math and DRM task literatures to explain these results.


Subject(s)
Cognition , Mental Recall , Recognition, Psychology , Repression, Psychology , Adult , Female , Humans , Individuality , Male , Mathematics , Middle Aged , Models, Psychological , Problem Solving , Semantics
13.
Am J Vet Res ; 62(4): 516-20, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11327457

ABSTRACT

OBJECTIVE: To determine how viral shedding and development or lack of clinical disease relate to contact transmission of vesicular stomatitis virus New Jersey (VSV-NJ) in pigs and determine whether pigs infected by contact could infect other pigs by contact. ANIMALS: 63 pigs. PROCEDURE: Serologically naive pigs were housed in direct contact with pigs that were experimentally inoculated with VSV-NJ via ID inoculation of the apex of the snout, application to a scarified area of the oral mucosa, application to intact oral mucosa, or ID inoculation of the ear. In a second experiment, pigs infected with VSV-NJ by contact were moved and housed with additional naive pigs. Pigs were monitored and sampled daily for clinical disease and virus isolation and were serologically tested before and after infection or contact. RESULTS: Contact transmission developed only when vesicular lesions were evident. Transmission developed rapidly; contact pigs shed virus as early as 1 day after contact. In pens in which contact transmission was detected, 2 of 3 or 3 of 3 contact pigs were infected. CONCLUSIONS AND CLINICAL RELEVANCE: Transmission was lesion-dependent; however, vesicular lesions often were subtle with few or no clinical signs of infection. Contact transmission was efficient, with resulting infections ranging from subclinical (detected only by seroconversion) to clinical (development of vesicular lesions). Long-term maintenance of VSV-NJ via contact transmission alone appears unlikely. Pigs represent an efficient large-animal system for further study of VSV-NJ pathogenesis and transmission.


Subject(s)
Disease Transmission, Infectious/veterinary , Rhabdoviridae Infections/veterinary , Stomatitis/veterinary , Swine Diseases/transmission , Vesiculovirus/growth & development , Animals , Antibodies, Viral/blood , Neutralization Tests , Rhabdoviridae Infections/transmission , Rhabdoviridae Infections/virology , Stomatitis/virology , Swine , Swine Diseases/virology , Virus Shedding
14.
J Exp Psychol Learn Mem Cogn ; 27(2): 328-38, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11294435

ABSTRACT

Using the Deese-Roediger-McDermott task and E. Tulving's (1985) remember-know judgments for recognition memory, the authors explored whether emotional words can show the false memory effect. Participants studied lists containing nonemotional, orthographic associates (e.g., cape, tape, ripe; part, perk, dark) of either emotional (e.g., rape) or nonemotional (e.g., park) critical lures. This setup produced significant false "remembering" of emotional lures, even though initially no emotional words appeared at study. When 3 emotional nonlure words appeared at study, emotional-lure false recognition more than doubled. However, when these 3 study words also appeared on the recognition test, false memory for the emotional lures was reduced. Across experiments, participants misremembered nonemotional lures more often than they did emotional lures, but they were more likely to rate emotional lures as "remembered," once they had been recognized as "old." The authors discuss findings in light of J. J. Freyd and D. H. Gleave's (1996) criticisms of this task.


Subject(s)
Attention , Emotions , Paired-Associate Learning , Repression, Psychology , Adult , Cues , Female , Humans , Male , Retention, Psychology , Semantics
15.
Mem Cognit ; 27(1): 106-15, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10087860

ABSTRACT

In four experiments, we examined the generation effect for the free recall of simple multiplication answers. Large-product-size problems showed a consistent generation-effect advantage over small-product-size problems, except when each answer was generated twice, via two different sets of operands (Experiment 2). Also, measures of problem-solution time and strategy use accounted for the large-product-size advantage. Across experiments, however, small-product-size problems (but not large-product-size problems) showed considerable variation in the size of their generation effect. We discovered that solving small-product-size problems via direct memory retrieval increased the episodic recall probability of other problems that were near neighbors to the generated answer, and we attribute this result to a spreading activation mechanism in semantic memory. A measure of neighbor activations, combined with RT to solve each problem, accounted for 51% of the observed generation-effect variance.


Subject(s)
Attention , Mental Recall , Problem Solving , Adolescent , Adult , Female , Humans , Male , Retention, Psychology
16.
Nature ; 393(6684): 487-91, 1998 Jun 04.
Article in English | MEDLINE | ID: mdl-9624007

ABSTRACT

Checkpoint controls ensure that events of the cell-division cycle are completed with fidelity and in the correct order. In budding yeast with a mutation in the motor protein dynein, the mitotic spindle is often misaligned and therefore slow to enter the neck between mother cell and budding daughter cell. When this occurs, cytokinesis (division of the cytoplasm into two) is delayed until the spindle is properly positioned. Here we describe mutations that abolish this delay, indicating the existence of a new checkpoint mechanism. One mutation lies in the gene encoding the yeast homologue of EB1, a human protein that binds the adenomatous polyposis coli (APC) protein, a tumour suppressor. EB1 is located on microtubules of the mitotic spindle and is important in spindle assembly. EB1 may therefore, by associating with microtubules, contribute to the sensor mechanism that activates the checkpoint. Another mutation affects Stt4, a phosphatidylinositol-4-OH kinase. Cold temperature is an environmental stimulus that causes misalignment of the mitotic spindle in yeast and appears to activate this checkpoint mechanism.


Subject(s)
Cell Division/physiology , Cytoskeletal Proteins/physiology , Fungal Proteins/physiology , Microtubule-Associated Proteins/physiology , Saccharomyces cerevisiae Proteins , 1-Phosphatidylinositol 4-Kinase/metabolism , Adenomatous Polyposis Coli Protein , Cytoskeletal Proteins/metabolism , Fungal Proteins/metabolism , Genes, Fungal , Genes, cdc , Microtubules/physiology , Mutation , Protein Binding , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/physiology , Spindle Apparatus/physiology , Temperature , Videotape Recording
17.
Gravit Space Biol Bull ; 11(2): 15-21, 1998 May.
Article in English | MEDLINE | ID: mdl-11540634

ABSTRACT

Eggs of Xenopus laevis and many other amphibians contain a gradient of yolk platelets along the animal-vegetal axis. Small platelets predominate in the animal hemisphere, and a boundary between medium and large yolk platelets exists near the equator. The blastopore forms at this boundary at the beginning of gastrulation, in the vegetal hemisphere. Does this boundary have a role in determination of the position of the blastopore, or does cortical information predominate? Past experiments using 1g to invert the egg showed a distinct tendency to form the blastopore in the original vegetal hemisphere. Our experiments, however, have used 20g centrifugation to achieve a more complete inversion of the yolk gradient. The blastopore formed in the original animal hemisphere in >95% of surviving gastrulae, if centrifugation was begun at normalized time 0.20-0.25 of the first cell cycle. Nearly normal larvae (DAI grades 4 and 5) form in 64% of cases (ave. DAI = 3.2). These data support the idea that the position of the blastopore depends on the position of the egg's internal contents rather than cortical determinants.


Subject(s)
Body Patterning/physiology , Gastrula/physiology , Hypergravity , Ovum/physiology , Xenopus laevis/embryology , Animals , Cell Polarity , Centrifugation , Developmental Biology , Embryo, Nonmammalian/physiology , Female , Gastrula/cytology , Male , Sperm-Ovum Interactions
18.
J Biol Chem ; 270(49): 29151-61, 1995 Dec 08.
Article in English | MEDLINE | ID: mdl-7493941

ABSTRACT

SW15 encodes a zinc finger DNA binding protein required for the transcription of the Saccharomyces cerevisiae HO gene, and PHO2 encodes a homeodomain DNA binding protein. In vitro biochemical studies using purified Swi5p and Pho2p proteins have demonstrated that Swi5p and Pho2p bind cooperatively to the HO promoter. In this report we investigate the regions of the Swi5p and Pho2p proteins required for cooperative DNA binding. The analysis of each protein gives a similar result: the zinc finger or homeodomain DNA binding domains are each sufficient for in vitro DNA binding, but additional regions of each protein are required for cooperative DNA binding. In vitro and in vivo experiments were conducted with promoters with altered spacing between the Pho2p and Swi5p binding sites. Mutations that increased the distance between the two binding sites had minimal effects on either in vitro cooperative DNA binding or in vivo upstream activating sequence activity. These observations suggest that the interaction domains of Swi5p and Pho2p are flexible and can tolerate an increase in distance between the two binding sites. The mechanism of the cooperative DNA binding by Swi5p and Pho2p is discussed.


Subject(s)
Cell Cycle Proteins , DNA-Binding Proteins/metabolism , DNA/metabolism , Fungal Proteins/metabolism , Homeodomain Proteins , Promoter Regions, Genetic , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae/genetics , Trans-Activators/metabolism , Transcription Factors/metabolism , Base Sequence , Binding Sites , Fungal Proteins/chemistry , Molecular Sequence Data , Trans-Activators/chemistry , Transcription Factors/chemistry
19.
J Am Diet Assoc ; 95(1): 30-3, 1995 Jan.
Article in English | MEDLINE | ID: mdl-7798577

ABSTRACT

OBJECTIVE: This study compared measured resting energy expenditures to resting energy expenditures calculated using Harris-Benedict equations (HBEs) and the Cystic Fibrosis Consensus Committee equations (CFCCEs). DESIGN: We studied 31 preadolescent boys and girls with cystic fibrosis who ranged in age from 3.25 to 12.75 years old. The patients were afebrile and not in pulmonary distress. Measured resting energy expenditures were determined using a portable metabolic measurement cart with fully automated calibration and data management. The measured resting energy expenditures obtained were compared with values obtained using HBEs and CFCCEs. RESULTS: For each patient, the measured resting energy expenditure value was above the predicted resting energy expenditure values derived from HBEs (P < or = .0001) and CFCCEs (P < or = .01). APPLICATIONS: The HBEs and the CFCCEs underestimated the energy expenditures of the study population by 13% and 8%, respectively. These findings support the usefulness of the measurement of energy expenditures in determining the energy needs of preadolescent patients with cystic fibrosis. In clinical practice, the resting energy expenditures would be multiplied by activity coefficients to determine the total daily energy expenditures of this population.


Subject(s)
Basal Metabolism , Cystic Fibrosis/metabolism , Body Height , Body Weight , Calorimetry, Indirect , Child , Child, Preschool , Female , Humans , Male , Mathematics
20.
Neuron ; 8(3): 399-413, 1992 Mar.
Article in English | MEDLINE | ID: mdl-1550669

ABSTRACT

The development of the neural retina follows a stereotyped time course that begins with an undifferentiated neuroepithelium populated by multipotential progenitor cells and ends with a highly differentiated tissue containing diverse cell types. The identities of the factors that guide this differentiation have remained elusive; a likely location for such factors, however, is the extracellular environment. Here, we show that the extracellular matrix component s-laminin is present in the neural retina, that s-laminin expression parallels the differentiation of rod photoreceptors, that photoreceptors interact with s-laminin in vitro, and that antibodies to s-laminin profoundly reduce the appearance of cells that express rhodopsin in vitro. These data suggest that s-laminin plays a role in the differentiation of the neural retina and provide evidence that the composition of the extracellular matrix may be an important determinant of retinal differentiation.


Subject(s)
Laminin/metabolism , Photoreceptor Cells/cytology , Retina/metabolism , Animals , Blotting, Western , Cell Adhesion , Cell Differentiation , Extracellular Matrix/metabolism , Retina/embryology , Skates, Fish
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