Search

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Soft matter on 29/03/2023, available online at: http://www.tandfonline.com/10.1039/d2sm01326f Cell migration is a physical process central to life. Among others, it regulates embryogenesis, tissue regeneration, and tumor growth. Therefore, understanding and controlling cell migration represent fundamental challenges in science. Specifically, the ability of cells to follow stiffness gradients, known as durotaxis, is ubiquitous across most cell types. Even so, certain cells follow positive stiffness gradients while others move along negative gradients. How the physical mechanisms involved in cell migration work to enable a wide range of durotactic responses is still poorly understood. Here, we provide a mechanistic rationale for durotaxis by integrating stochastic clutch models for cell adhesion with an active gel theory of cell migration. We show that positive and negative durotaxis found across cell types are explained by asymmetries in the cell adhesion dynamics. We rationalize durotaxis by asymmetric mechanotransduction in the cell adhesion behavior that further polarizes the intracellular retrograde flow and the protruding velocity at the cell membrane. Our theoretical framework confirms previous experimental observations and explains positive and negative durotaxis. Moreover, we show how durotaxis can be engineered to manipulate cell migration, which has important implications in biology, medicine, and bioengineering. P.S acknowledges support from the Spanish Ministry of Economy and Competitiveness (Grant No: PID2019-110949GB-I00) and the Generalitat de Catalunya (Grant No: 2017-SGR-1278). C.V. was supported by the Generalitat de Catalunya (FI grant). P.S and C.V. acknowledge support from the European Commission (Grant No. H2020-FETPROACT-01-2016-731957). We also thank W. Mirza, J.J. Muñoz, and M. Arroyo for discussion.

Cell-matrix adhesion is a central mechanical function to a large number of phenomena in physiology and disease, including morphogenesis, wound healing and tumor cell invasion. Today, how single cells responds to different extracellular cues has been comprehensibly studied. However, how the mechanical behavior of the main individual molecules that form an adhesion complex cooperatively respond to force within the adhesion complex has not been addressed. This is a key aspect in cell adhesion because how these cell adhesion molecules respond to force determines not only cell-matrix behavior but, ultimately, cell function. To answer this question, we develop a multi-scale computational model for adhesion complexes mechanics. Based on the classical clutch hypothesis, we model individual adhesion chains made of a contractile actin network, a talin rod and an integrin molecule that binds at individual adhesion sites on the extracellular matrix. We explore several scenarios of integrins dynamics and analyze the effects of diverse extracellular matrices on the behavior of the adhesion molecules and on the whole adhesion complex. Our results explains how every single component of the adhesion chain mechanically responds to the contractile actomyosin force and show how they control the tractions forces exerted by the cell on the extracellular space. Importantly, our computational results are in agreement with previous experimental data both at the molecular and cell level. Our multi-scale clutch model presents a step forward not only to further understand adhesion complexes mechanics but also to, e.g., engineer better biomimetic materials, repair biological tissues or arrest invasive tumor migration.Author summaryCell-matrix adhesions are directly implicated in key biological processes such as tissue development, regeneration and tumor cell invasion. These cell functions are determined by how adhesion complexes feel and respond to mechanical forces. Still, how forces are transmitted through the individual cell adhesion molecules that integrate the adhesion complex is poorly understood. To address this issue, we develop a multi-scale clutch model for adhesion complexes where individual adhesion chains, made of integrin and talin molecules, are considered within classical clutch models. This approach provides a rich mechanosensivity insight of how the mechanics of cell adhesion works. It allows to integrate accurate biophysical models of individual adhesion molecules into whole adhesion complex models. Our multi-scale clutch approach allows to extend our current knowledge of adhesion complexes for physiology and disease, e.g., the regeneration of biological tissues or arrest invasive tumor migration, and for engineering better biomimetic materials.

Cell migration is a physical process central to life. Among others, it regulates embryogenesis, tissue regeneration and tumor growth. Therefore, understanding and controlling cell migration represent fundamental challenges in science. Specifically, the ability of cells to follow stiffness gradients, known as durotaxis, is ubiquitous across most cell types. Even so, certain cells follow positive stiffness gradients while others move along negative gradients. How the physical mechanisms involved in cell migration works to enable a wide range of durotactic responses is still poorly understood. Here, we provide a mechanistic rationale of durotaxis by integrating stochastic clutch models for cell adhesion with an active gel theory of cell migration. We show that positive and negative durotaxis found across cell types are explained by asymmetries in the cell adhesion dynamics. We rationalize durotaxis by an asymmetric mechanotransduction in the cell adhesion behavior that further polarizes the intracellular retrograde flow and the protruding velocity at the cell membrane. Our theoretical framework confirms previous experimental observations and explains positive and negative durotaxis. Moreover, we show how durotaxis can be engineer to manipulate cell migration, which has important implications in biology, medicine and bioengineering.

Purpose: Deformation analysis from 3D echocardiography results in a considerable amount of parameters, for which the conventional statistical approach is cumbersome. We investigate local motion and deformation patterns to determine the parameters of relevance for the study of LV myocardial deformation in the presence of LAD infarct. Methods: The study included 46 patients acquired at max. 5 days after LAD infarct (37 sequences) and at 1-year follow-up (33 sequences), and 46 controls. Patients were selected if they had a LVEF

Purpose: No consensus exists for the diagnosis of heart failure with preserved ejection fraction (HFPEF). Current studies recommend stress echocardiography protocols, but single standard peak or timing measurements are limited towards the complexity of the disease. We show the contribution of a combined analysis of multiple myocardial velocity patterns and investigate their relative relevance for the characterization of HFPEF. Methods: Velocity traces from 55 subjects were examined (69±6 years, 22 healthy, 19 HFPEF and 14 breathless subjects). Data came from tissue Doppler acquisitions at rest and exercise at the basal septum and lateral wall, and were temporally aligned to a common reference for comparison. Each phase of the cycle at each stage of the protocol was identified for analysis (figure). Unsupervised machine learning (multiple kernel learning) was used to characterize this population and automatically determine the relevance of each velocity pattern. Results: The learning found a discrimination algorithm that performed well in agreement with diagnosis based on current guidelines (sens=78.9%, spec=86.3%, K=0.65). The importance given to early diastole at exercise was substantially higher, while the isovolumic contraction was the lowest contributor. The breathless subjects were associated to their closest subgroup. Conclusion: The characterization of HFPEF is improved by a combined analysis of multiple velocity traces from stress echo studies using machine learning. The method additionally suggests features of interest to be used in clinical diagnosis.

A new fluorophore containing 2,1,3-benzothiadiazole unit with alkylated tetrazole terminal groups as electron donors connected through a π-conjugated system of the type (D-π-A-π-D) was synthesized using the Sonogashira coupling reaction with good yields. The genotoxicity of the two intermediate compounds and the final product was evaluated in vitro in consideration of the potential application of the new compound in the chemical production of photovoltaic paints. The new fluorophore did not show significant biological effects in the cell viability test and the comet assay when compared with the intermediate compounds that were obtained synthetically despite the ability to interact with deoxyribonucleic acid (DNA) as demonstrated in circular dichroism assays. Thus, the compound does not show toxic or genotoxic activity, and therefore, it can be applied as a pigment in photovoltaic paint.

Background Mesenchymal stem cells (MSCs) are pleuripotent bone marrow and tissue resident cells implicated in homeostasis and tissue repair. Systemic sclerosis (scleroderma, SSc) is a severe connective tissue disease characterised by progressive fibrotic thickening of the dermis, accompanied by loss of subcutaneous fat and microvasculature. Aberrant activation of MSCs within the disease microenvironment may underly the persistent fibrotic repair process, or account for the failure of adipogenesis and dysregulated vascular repair. Objectives We sought to: 1) determine whether activated MSCs are present within the SSc involved skin lesions, 2) test whether SSc suction blister fluid (BF) derived from involved forearm skin can induce phenotype changes in MSCs, 3) fully profile the altered gene expression in MSCs exposed to SSc BF, 4) investigate the role of key factors present at increased level in SSc BF (IL-31, lactate). Methods Novel post-fixation collagenase tissue dissociation techniques applied to 1 mm tissue sections, combined with Feulgen staining of DNA, were used to identify MSCs undergoing metakaryotic division within the involved skin of SSc patients. Fat derived MSCs from healthy controls were treated in tissue culture with blister fluid derived from the fibrotic skin lesions or from matched sites in healthy individuals, or exposed to key constituent factors, including cytokines (IL-31, 50 ng/ml), metabolites (lactate, 25 mM), and enhanced stiffness matrix (50 kPa gels). The responses of MSCs were studied by analysis of next generation sequencing (NGS) and phenotype changes. Results MSCs undergoing metakaryotic division were identified in SSc skin biopsy material but not in healthy control (HC) tissue (SSc vs HC, superficial dermis 0 vs 0, mid dermis 1.1 vs 0 p Conclusions Factors present at elevated levels in the disease microenvironment, including cytokines and metabolites, as well as the stiffened ECM, are capable of promoting the migration and differentation of fat derived MSCs, towards tissue reparative cells implicated in the fibrotic process. Conversely, the adipogenic and vascular regenerative potential of these cells may be reduced by exposure to the SSc microenvironment. Disclosure of Interest None declared

Aim To determine whether the outcomes of home enteral nutrition for frail older patients can be improved by video consultation between home visiting staff and a hospital physician, specialized in clinical nutrition, during monthly home visits. Methods A randomized prospective study out of patients aged older than 65 years receiving home enteral nutrition from the Department of Clinical Nutrition of an Italian geriatric hospital in 2013 was carried. A total of 100 patients were randomly assigned to receive video consultation in addition to regular monthly home visits, 88 patients only had regular monthly home visits. Therapy outcomes – incidence rates of complications, outpatient hospital visits and hospitalizations – were compared between two groups. A logistic regression analysis was carried out to evaluate the usefulness of the video consultation to improve therapy outcomes. Results Incidence rates for metabolic and gastrointestinal complications were significantly lower for patients who received a video consultation, respectively: 0.032/year “video consultation” versus 0.055/year “no video consultation” (P = 0.0001) and 0.006/year “video consultation” versus 0.028/year “no video consultation” (P

The aim of this study was to estimate genetic and phenotypic associations of growth traits with carcass and meat traits in Nellore cattle. Data from male and female animals were used for weaning weight (WW; N = 241,416), yearling weight (YW, N = 126,596), weight gain from weaning to yearling (GWY, N = 78,687), and yearling hip height (YHH, N = 90,720), respectively; 877 male animals were used for hot carcass weight (HCW) and 884 for longissimus muscle area (LMA), backfat thickness (BT), marbling score (MS), and shear force (SF). The variance components were estimated by the restricted maximum likelihood method using three-trait animal models that included WW. The model for WW included direct and maternal additive genetic, maternal permanent environmental, and residual effects as random effects; contemporary group as fixed effects; and age of dam at calving and age of animal as covariates (linear and quadratic effects). For the other traits, maternal effects and the effect of age of dam at calving were excluded from the model. Heritability ranged from 0.10 ± 0.12 (LMA) to 0.44 ± 0.007 (YW). Genetic correlations ranged from -0.40 ± 0.38 (WW x LMA) to 0.55 ± 0.10 (HCW x YW). Growth, carcass, and meat traits have sufficient genetic variability to be included as selection criteria in animal breeding programs.

Summary Background and aims European and international guidelines advice against initiating tube-feeding in patients with severe dementia. These recommendations are based on studies with important methodological limitations that evaluated the benefits of artificial nutrition in patients with percutaneous endoscopic gastrostomy almost exclusively in terms of the prolongation of survival. The aims of this study were to assess the harmful effects of home enteral nutrition administered via the nasogastric tube and percutaneous endoscopic gastrostomy in patients with advanced dementia in terms of mechanical, gastrointestinal and metabolic complications, to estimate the survival, to explore the risk factors for mortality and to compare the outcomes of patients with advanced dementia with those of patients without dementia. Methods The retrospective observational study was carried out on 585 consecutive patients of the mean age of 85.6 ± 6.9 years. They were treated using home enteral nutrition from 2010 to 2015 according to follow-up protocols adopted by the Clinical Nutrition Unit of an Italian geriatric research hospital (IRCCS-INRCA, Ancona). Incidence rates of mechanical, gastrointestinal and metabolic complications and survival rates in patients with severe dementia were compared to those in patients without dementia. The Cox proportional hazards model was used to evaluate the mortality risk factors. Results There was no difference between the incidence rates of complications in patients with severe dementia and those in patients without dementia. The incidence of mechanical complications was 1.35/1000 days for patients without dementia vs. 1.53/1000 days for patients with dementia (p = 0.270), the incidence of gastrointestinal complications was 1.30/1000 days for patients without dementia vs. 1.35/1000 days for patients with dementia (p = 0.984) and the incidence of metabolic complications was 0.36/1000 days for patients without dementia vs. 0.35/1000 days for patients with dementia (p = 0.252). The Kaplan Mailer analyses showed that there was no evidence to support the theses on poorer prognosis of survival of patients with dementia (median survival was 193 days for patients without dementia vs. 192 days for patients with dementia, (p > 0.05)). The female gender, advanced age, nasogastric tube, diabetes mellitus and chronic renal failure were identified as risk factors. Subjects whose Geriatric Nutritional Risk Index values were higher had a lower risk of mortality. Conclusions The discussion on the appropriateness of enteral nutrition in patients with severe dementia is still open. Our results show that, if there is a medical prescription for tube-feeding and a patient's surrogate decision-makers express free and informed consent to the tube-feeding of the patient, enteral nutrition should not be contraindicated a priori if the patient has severe dementia. Regular follow-up is mandatory to guarantee adherence to the therapy and achieve its initial aims and to ensure that the principles of beneficence and nonmaleficence are respected.

Congenital toxoplasmosis diagnosis in the newborn is a very important issue due to the need for early treatment to prevent future sequels. Aim To compare available methods at the institution for the diagnosis of congenital toxoplasmosis. Material and Methods In this study we have evaluated the different diagnostic tests used in 67 congenital exposed newborns, including serological tests, PCR, parasite isolation and molecular characterization. Results The ISAGA IgM and IgA tests showed sensitivity (Se) of 87 and 91%, respectively, and specificity (Sp) of 100%. When ISAGA IgM and IgA were performed simultaneously, the Se increased to 98% and the Sp was 100%. The presence of IgE contributed to the diagnosis when it was detected in the child's serum but not in maternal blood. In four congenital infected children the parasite was isolated and genotyped: one was genotype II and the other three were "atypical" genotypes. No parasite was isolated in children without congenital toxoplasmosis. Discussion Overall, serological tests showed a good diagnostic performance although in one case they were all negative and isolation was the only tool to identify the infection. We conclude that it is essential to use all diagnostic tests in every single exposed child, including if possible, molecular characterization due to its epidemiological implication.

The aim of this study was to identify single-nucleotide polymorphisms (SNPs) in buffaloes associated with milk yield and content, in addition to somatic cell scores based on the cross-species transferability of SNPs from cattle to buffalo. A total of 15,745 SNPs were analyzed, of which 1562 showed 1% significance and 4742 with 5% significance, which were associated for all traits studied. After application of Bonferroni's correction for multiple tests of the traits analyzed, we found 2 significant SNPs placed on cattle chromosomes BTA15 and BTA20, which are homologous to buffalo chromosomes BBU16 and BBU19, respectively. In this genome association study, we found several significant SNPs affecting buffalo milk production and quality. Furthermore, the use of the high-density bovine BeadChip was suitable for genomic analysis in buffaloes. Although extensive chromosome arm homology was described between cattle and buffalo, the exact chromosomal position of SNP markers associated with these economically important traits in buffalo can be determined only through buffalo genome sequencing.

OBJECTIVE: To assess the prevalence of malnutrition according to the new ESPEN definition in a population of geriatric hospital patients and to determine how malnutrition affects the length of hospital stay (LOS) and hospital mortality. DESIGN: A retrospective analysis of data gathered during nutritional screening surveys carried out three consecutive years, from 2012 to 2014, in an Italian geriatric research hospital (INRCA, Ancona) was performed. On the day of the study, demographic data, data on clinical conditions and the nutritional status of newly admitted patients were collected. Patients were screened for malnutrition risk using the Malnutrition Universal Screening Tool (MUST). Subsequently, malnutrition was diagnosed, for subjects at high risk, following the criteria suggested by the European Association for Clinical Nutrition and Metabolism [body mass index (BMI) < 18.5 kg/m2 or different combinations of unintentional weight loss over time and BMI values]. Sensitivity, specificity, positive and negative predictive value of MUST compared to ESPEN criteria were assessed. The characteristics of patients with a diagnosis of malnutrition were compared to those of non-malnourished patients. The impact of malnutrition on LOS and hospital mortality was investigated through logistic and linear regression models. SETTING: The study was performed in an Italian geriatric research hospital (INRCA, Ancona). SUBJECTS: Two hundred eighty-four newly hospitalized geriatric patients from acute care wards (mean age 82.8 ± 8.7 years), who gave their written consent to participate in the study, were enrolled. RESULTS: According to the MUST, high risk of malnutrition at hospitalization was found in 28.2% of patients. Malnutrition was diagnosed in 24.6% of subjects. The malnutrition was an independent predictor of both the LOS and hospital mortality. The multivariate analyses—linear and logistic regression—were performed considering different potential confounders contemporarily. The results showed that the malnutrition is an independent predictor of LOS and hospital mortality. Malnourished subjects were hospitalized almost 3 days longer compared to non-malnourished patients (p = 0.047; CI 0.04–5.80). The risk of death during hospitalization was 55% higher for malnourished patients (p = 0.037; CI 0.21–0.95). CONCLUSION: A new ESPEN consensus of malnutrition was easily applicable in a population of geriatric hospital patients. Given that the nutritional status of geriatric patients was strongly correlated with the LOS and hospital mortality, the use of this simple and non-time consuming tool is highly recommended in clinical practice.

The study of genes associated with host defense mechanisms, such as the A2M gene, plays a critical role in preventing diseases that reduce milk yield and its constituents. The aim of this study was to identify polymorphisms in the A2M gene in Murrah buffaloes (Bubalus bubalis), and investigate their associations with milk yield, fat and protein production, fat and protein percentages, and somatic cell count. Hair follicle samples of 136 animals were collected for DNA extraction, and polymorphisms were identified by polymerase chain reactions and sequencing. Statistical analyses were performed to ascertain the allelic and genotypic frequencies, the Hardy-Weinberg equilibrium, and association analysis was conducted between the polymorphisms and the traits studied. Comparative analysis between buffalo and bovine sequences revealed seven nucleotide substitutions. Alignments among the buffalo sequences identified three single nucleotide polymorphisms (SNPs), including one in exon 29, g.241A>G, which was used in subsequent statistical analyses. A Hardy-Weinberg test indicated that this SNP was in equilibrium in this population, and was significantly associated (P < 0.05) with fat production and fat and protein percentages. Therefore, this SNP can be used as a molecular marker for these traits.

FS CMa type stars are a group of Galactic objects with the B[e] phenomenon. They exhibit strong emission-line spectra and infrared excesses, which are most likely due to recently formed circumstellar dust. The group content and identification criteria were described in the first two papers of the series. In this paper we report our spectroscopic and photometric observations of the optical counterpart of IRAS 00470+6429 obtained in 2003--2008. The optical spectrum is dominated by emission lines, most of which have P Cyg type profiles. We detected significant brightness variations, which may include a regular component, and variable spectral line profiles in both shape and position. The presence of a weak Li {\sc I} 6708 \AA line in the spectrum suggests that the object is most likely a binary system with a B2--B3 spectral type primary companion of a luminosity $\log$ L/L$\odot$ = 3.9$\pm$0.3 and a late-type secondary companion. We estimate a distance toward the object to be 2.0$\pm$0.3 kpc from the Sun., Comment: 37 pages, 13 figures

The dynamical structure factor of a two-dimensional electrons trapped to a helium film deposited on a solid substrate is determined through molecular dynamics simulations for different film thicknesses and two substrates. The phases of the system varying from the classical Wigner crystal to strong and intermediate- correlated electron liquid as well the influence of the film thickness and substrate are analyzed in the numerical experiments.

FS CMa stars form a group of objects with the B[e] phenomenon that were previously known as unclassified B[e] stars or B[e] stars with warm dust (B[e]WD) until recently. They exhibit strong emission-line spectra and strong IR excesses, most likely due to recently formed circumstellar dust. These properties have been suggested to be due to ongoing or recent rapid mass exchange in binary systems with hot primaries and various types of secondaries. The first paper of this series reported an analysis of the available information about previously known Galactic objects with the B[e] phenomenon, the initial selection of the FS CMa group objects, and a qualitative explanation of their properties. This paper reports the results of our new search for more FS CMa objects in the IRAS Point Source Catalog. We present new photometric criteria for identifying FS CMa stars as well as the first results of our observations of nine new FS CMa group members. With this addition, the FS CMa group has now 40 members, becoming

The 3-13 μm spectra of Deimos and Phobos were obtained on the nights of 2003 August 19, 20, and 21 UT, within a week of opposition (August 28). Spectra in the 1.5-2.5 μm region were taken a few weeks earlier on July 26. Observations were made near greatest elongation for each satellite in order to minimize scattered light from Mars. The L, M, and narrowband N (10.2 μm) magnitudes for Deimos were 7.7 ± 0.1, 4.9 ± 0.1, and 0.79 ± 0.09, respectively. The L, M, and narrowband N (10.2 μm) magnitudes for Phobos were 6.4, 3.8, and -0.52, respectively, all ±0.07. The 5-12 μm color temperatures of Deimos and Phobos were 344 ± 5 and 357 ± 5 K, respectively, significantly higher than the blackbody thermal equilibrium temperature for either a fast rotator at Mars's heliocentric distance (237 K) or a slow rotator (282 K). The high brightness temperatures of Deimos and Phobos in the thermal infrared of 310-330 and 320-340 K, respectively, are not understood, but they are somewhat consistent with the high color temperatures. Within the errors, there was little evidence for spectral features indicative of surface composition, although there were some 1-2 σ variations that warrant further observations.

The aim of this study was to estimate genetic parameters for prenatal (PRE) and postnatal (POS) mortality in Nellore cattle. A total of 13 141 (PRE) and 17 818 (POS) records from Nellore females were used. PRE and POS were recorded using binary scale scores: a score of '1' was given to calves that were born alive (PRE) and those that were alive at weaning (POS), and a score of '0' was given to calves that were not alive at or around birth (PRE), as well as to those weighed at birth but not at weaning (POS). The relationship matrix included 698 sires, 107 paternal grandsires and 69 maternal grandsires. Data were analysed using Bayesian inference and a sire-maternal grandsire threshold model, including contemporary groups as random effects, and the classes of dam age at the beginning of mating season (for PRE), and dam age at calving and birthweight (linear covariable) (for POS), as fixed effects. For both traits, the covariance between direct and maternal effects (rD,M ) was estimated (rD,M ≠ 0) or fixed at zero (rD,M = 0). PRE and POS rates were 3.00 and 4.04%, respectively. Estimates of direct and maternal heritability were 0.07 and 0.17, respectively, for PRE, and 0.02 and 0.07, respectively, for POS, assuming rD,M = 0. For rD,M ≠ 0, these estimates were 0.07 and 0.12, respectively, for PRE, and 0.03 and 0.07, respectively, for POS. The correlation estimates between direct and maternal effects were -0.71 (PRE) and -0.33 (POS). PRE and POS show low genetic variability, indicating that these traits probably suffer major environmental influences. Additionally, our study shows that the maternal genetic component affects preweaning calf mortality twice as much (or more) as the direct genetic component. A large number of offspring per sire is necessary in progeny tests to genetically decrease calf mortality.

The objective of this study was to evaluate associations between single nucleotide polymorphism (SNP) markers and carcass traits measured postmortem in Nellore cattle. Records of loin eye area (LEA) and backfat thickness (BF) from 740 males and records of hot carcass weight (HCW) from 726 males were analyzed. All of the animals were genotyped using the BovineHD BeadChip. Association analyses were performed by the restricted maximum likelihood method that considered one SNP at a time. Significant SNPs were identified on chromosomes 2 and 6 for LEA and on chromosomes 7, 1, and 2 for BF. For HCW, associations with SNPs were found on chromosomes 13, 14, and 28, in addition to genome regions that were directly related to this trait, such as the EFCAB8 and VSTM2L genes, and to bone development (RHOU). Some SNPs were located in very close proximity to genes involved in basal metabolism (BLCAP, NNAT, CTNNBL1, TGM2, and LOC100296770) and the immune system (BPI).

This study investigates the genetic association of the SNP present in the ACTA1 gene with performance traits, organs and carcass of broilers to help marker-assisted selection of a paternal broiler line (TT) from EMBRAPA Swine and Poultry, Brazil. Genetic and phenotypic data of 1,400 broilers for 68 traits related to body performance, organ weights, weight of carcass parts, and yields as a percentage of organs and carcass parts were used. The maximum likelihood method, considering 4 analytical models, was used to analyze the genetic association between the SNP and these important economic traits. The association analysis was performed using a mixed animal model including the random effect of the animal (polygenic), and the fixed effects of sex (2 levels), hatch (5 levels) and SNP (3 levels), besides the random error. The traits significantly associated (P

Summary Background & aims The purpose of this study was to comprehend and describe the views, experiences and adaptations of caregivers who assist older patients treated with Home Enteral Nutrition. The objective was to gather empirical evidence to improve the delivery of Home Enteral Nutrition for old patients taking into account the caregivers' support needs. Methods A qualitative methodology with focus groups as data collection method was used to collect the testimonies of 30 informal and formal caregivers of older patients treated with Home Enteral Nutrition by the Clinical Nutrition Service of INRCA (Ancona) during 2014. Quantitative methodology was used to collect socio-demographic data. Partially modified Silver's “Home Enteral Nutrition Caregiver Task Checklist” was used to identify training needs. The constant comparison method was used to code and categorize data and to develop themes of focus groups. Simple descriptive statistics were used to summarize questionnaires. Results Five main themes were identified from focus groups: acceptance of the therapy, skill acquisition process, need for psychological and practical support at home from healthcare professionals, lifestyle adaptation, affirmation of life and family. All caregivers testified the initial fear and refusal to manage the nutrition pump and the therapy. They expressed the need to be trained gradually, starting during a patient's hospitalization, and continuing in the community. With reference to their overall QoL, it emerged that informal caregivers suffered mostly from the reduction of their free time while formal caregivers suffered social isolation and psychological burden. For both groups the monthly home visit was the most important element of the HEN service. Informal caregivers highlighted the importance of having their loved ones at home. Unsatisfied training needs were identified by the modified Silver's “Home Enteral Nutrition Caregiver Task Checklist”. Conclusions This qualitative study underlined the challenges and adaptations of caregivers who assist older patients treated with Home Enteral Nutrition, which should be considered when defining clinical protocols and supporting caregivers.

The objective of this study was to quantify the magnitude of genotype-environment interaction (GxE) effects on age at first calving (AFC), scrotal circumference (SC), and yearling weight (YW) in Nellore cattle using reaction norms. For the study, 89,152 weight records of female and male Nellore animals obtained at yearling age were used. Genetic parameters were estimated with a single-trait random-regression model using Legendre polynomials as base functions. The heritability estimates were of low to medium magnitude for AFC (0.05 to 0.47) and of medium to high magnitude for SC (0.32 to 0.51) and YW (0.13 to 0.72), and increased as the environmental gradient became more favorable. The genetic correlation estimates ranged from 0.25 to 1.0 for AFC, from 0.71 to 1.0 for SC, and from 0.42 to 1.0 for YW. High Spearman correlation coefficients were obtained for the three traits, ranging from 0.97 to 0.99. The reaction norms along the environmental gradient of 10 sires each with the highest or lowest breeding value for YW predicted by single-trait analysis demonstrated more plastic phenotypes for YW and more robust phenotypes for SC. The effect of GxE was most important for YW and AFC with respect to SC. When animals are selected for higher SC or YW or lower AFC, considering or not the GxE effect, it is expected that the same animals will be selected. The reaction norms obtained based on sire breeding values along the environmental gradient showed that animals with extreme breeding values respond differently as environmental conditions improve.

Made available in DSpace on 2022-05-02T15:13:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-04-01 The aim of this study was to evaluate the effect of genotype × environment interaction (G×E) on age at first calving (AFC), scrotal circumference (SC), and yearling weight (YW) and to estimate genetic correlations between these traits in Nellore cattle using reaction norms in multitrait random regression models. In this study, 28,871, 41,386, and 89,152 records of Nellore cattle for AFC, SC, and YW, respectively, were used. The data were obtained from farms located in the north, northeast, midwest, and southeast regions of Brazil that participate in the DeltaGen Breeding Program. Environmental levels were defined as a function of contemporary groups, that is, animals born in the same herd and year, from the same management group (from birth to yearling), and of the same sex. Postweaning weight gain was used as a criterion to evaluate the environmental conditions for all traits. For reaction norm analyses, residual variances were modeled with homogeneous and heterogeneous classes. The model for SC and YW included the fixed effects of contemporary group and age of the animal as a covariate as well as random direct additive genetic and residual effects. The same model, excluding the covariate age of the animal, was used for AFC. The heritability estimates were low to high for AFC (0.09 to 0.50), high for SC (0.51 to 0.67), and moderate to high for YW (0.33 to 0.71). The genetic correlations (within each trait) along the environmental levels varied from –0.27 to 1.0 for AFC, from 0.73 to 1.0 for SC, and from 0.26 to 1.0 for YW. The genetic correlations between different traits in different environments varied from –0.14 to –0.60 between AFC and SC, from –0.05 to –0.32 between AFC and YW, and from –0.05 to 0.72 between YW and SC. The genetic correlations have had different magnitudes for AFC, SC, and YW, which could indicate the presence of G×E. The present results should support researchers and farmers in defining selection criteria to improve growth traits and sexual precocity. Our results suggest that animals for breeding have to be selected in the same environment and management conditions as their progeny will be reared. Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista Júlio de Mesquita Filho