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1.
Phys Rev Lett ; 126(20): 206805, 2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34110210

RESUMO

We show that a simple one-dimensional model of spinless fermions with pair hopping displays a phase in which a Luttinger liquid of paired fermions coexists with a Luttinger liquid of unpaired fermions. Our results are based on extensive numerical density-matrix renormalization-group calculations and are supported by a two-fluid model that captures the essence of the coexistence region.

2.
Phys Rev Lett ; 120(15): 157201, 2018 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-29756857

RESUMO

Recently, the frustrated XY model for spins 1/2 on the honeycomb lattice has attracted a lot of attention in relation with the possibility to realize a chiral spin liquid state. This model is relevant to the physics of some quantum magnets. Using the flexibility of ultracold atom setups, we propose an alternative way to realize this model through the Mott regime of the bosonic Kane-Mele-Hubbard model. The phase diagram of this model is derived using bosonic dynamical mean-field theory. Focusing on the Mott phase, we investigate its magnetic properties as a function of frustration. We do find an emergent chiral spin state in the intermediate frustration regime. Using exact diagonalization we study more closely the physics of the effective frustrated XY model and the properties of the chiral spin state. This gapped phase displays a chiral order, breaking time-reversal and parity symmetry, but is not topologically ordered (the Chern number is zero).

3.
Rev Med Suisse ; 13(556): 698-702, 2017 Mar 29.
Artigo em Francês | MEDLINE | ID: mdl-28722380

RESUMO

An algorithm is proposed to facilitate the management of onychomycosis and ensure a good therapeutical approach. Its aim is to simplify the diagnosis process by integrating a pertinent anamnesis and physical examination with the classic tool of mycology (direct examination, culture, eventually examination by PCR), in order to give the adequate targeted treatment.


Cet article propose un algorithme afin de faciliter la prise en charge thérapeutique et diagnostique de l'onychomycose. Il vise à simplifier la démarche diagnostique jusqu'à l'identification du champignon dont dépendra le traitement. Il permet de rappeler que toute onychodystrophie n'est pas une onychomycose.


Assuntos
Algoritmos , Dermatoses do Pé/diagnóstico , Onicomicose/diagnóstico , Dermatoses do Pé/terapia , Humanos , Onicomicose/terapia , Exame Físico/métodos , Reação em Cadeia da Polimerase
4.
Phys Rev Lett ; 113(9): 095301, 2014 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-25215990

RESUMO

We employ ultracold atoms with controllable disorder and interaction to study the paradigmatic problem of disordered bosons in the full disorder-interaction plane. Combining measurements of coherence, transport and excitation spectra, we get evidence of an insulating regime extending from weak to strong interaction and surrounding a superfluidlike regime, in general agreement with the theory. For strong interaction, we reveal the presence of a strongly correlated Bose glass coexisting with a Mott insulator.

6.
Phys Rev Lett ; 110(8): 087204, 2013 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-23473195

RESUMO

We study the effect of disorder on frustrated dimerized spin-1/2 chains at the Majumdar-Ghosh point. Using variational methods and density-matrix renormalization group approaches, we identify two localization mechanisms for spinons which are the deconfined fractional elementary excitations of these chains. The first one belongs to the Anderson localization class and dominates at the random Majumdar-Ghosh point. There, spinons remain gapped and localize in Lifshitz states whose localization length is analytically obtained. The other mechanism is a random confinement mechanism which induces an effective interaction between spinons and brings the chain into a gapless and partially polarized phase for arbitrarily small disorder.

7.
Adv Life Course Res ; 56: 100530, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-38054879

RESUMO

In this paper, we propose a sequence analysis-based method for selecting qualitative cases depending on quantitative results. Inspired by tools developed for cross-sectional analyses, we propose indicators suitable for longitudinal study of the life course in a holistic perspective and a set of corresponding analysis guidelines. Two complementary indicators are introduced, marginality and gain, that allows labeling observations according to both their typicality within their group and their illustrativeness of a given quantitative relationship. These indicators allow selecting a diversity of cases depending on their contributions to a quantitative relationship between trajectories and a covariate or a typology. The computation of the indicators is made available in the TraMineRextras R package. The method and its advantages are illustrated through an original study of the relationships between residential trajectories in the Paris region and residential socialization during childhood. Using the Biographies et Entourage [Event history and entourage] survey and qualitative interviews conducted with a subsample of respondents, the analysis shows the contributions of the method not only to improve the understanding of statistical associations, but also to identify their limitations. Extension and generalization of the method are finally proposed to cover a wider scope of situations.


Assuntos
Generalização Psicológica , Acontecimentos que Mudam a Vida , Humanos , Estudos Transversais , Estudos Longitudinais , Paris
8.
Orthop Traumatol Surg Res ; 109(1): 103467, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36999994

RESUMO

BACKGROUND: Surgery for displaced intra-articular calcaneal fractures (DIACFs) is often followed by skin complications that adversely impacts the functional outcomes. Minimally invasive techniques have been developed to decrease the risk of skin complications. The objective of this study was to compare C-Nail® locking-nail fixation to conventional plate fixation for DIACFs. HYPOTHESIS: C-Nail® fixation restores calcaneal anatomy similarly to conventional plate fixation and decreases the frequency of skin complications compared to conventional plate fixation, while providing satisfactory functional outcomes. MATERIAL AND METHODS: In this case-control study of DIACFs, fixation was with a non-locking plate in 30 patients treated between January 2016 and June 2017 and with the C-Nail® in 25 patients treated between April 2017 and April 2018. Computed tomography was performed before surgery then bilaterally after surgery for measurements of the following calcaneal parameters: height, length, width, joint-surface step-off and inter-fragmentary distance. The values of these parameters were compared between the two groups. Postoperative skin complications were recorded. The functional outcome was assessed by determining the AOFAS score 1 year after the injury. RESULTS: The two groups showed no significant differences for age, sex or fracture type. Wound healing was delayed in 3 patients in the plate group. The mean postoperative values of the calcaneal parameters were not significantly different between the two groups. The mean AOFAS score was 85.3±10.4 (range, 50-100) in the plate group and 87.0±12.0 (range, 64-100) in the C-Nail® group (p>0.05). DISCUSSION: Minimally invasive C-Nail® fixation provides similar restoration of calcaneal anatomy as does conventional plate fixation. LEVEL OF EVIDENCE: III, retrospective case-control study.


Assuntos
Traumatismos do Tornozelo , Calcâneo , Traumatismos do Pé , Fraturas Ósseas , Fraturas Intra-Articulares , Humanos , Fixação Interna de Fraturas/métodos , Estudos Retrospectivos , Estudos de Casos e Controles , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/cirurgia , Fraturas Ósseas/etiologia , Calcâneo/diagnóstico por imagem , Calcâneo/cirurgia , Calcâneo/lesões , Placas Ósseas , Traumatismos do Pé/etiologia , Complicações Pós-Operatórias/etiologia , Resultado do Tratamento , Fraturas Intra-Articulares/cirurgia
9.
Chemotherapy ; 58(2): 134-41, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22572213

RESUMO

BACKGROUND: Systemic chemotherapy is the treatment of choice for inoperable (advanced or metastatic) cholangiocarcinoma. According to phase II and III trials, regimens combining 5-fluorouracil (5FU) or gemcitabine with a platinum salt have provided an overall response rate of 12-50% with a median overall survival of 5-16 months. METHODS: This was a retrospective analysis of 78 consecutive cases of inoperable cholangiocarcinoma treated by palliative chemotherapy from July 2005 to November 2009 in one center. We firstly aimed to evaluate the impact of palliative chemotherapy in terms of survival and secondly to analyze possible related prognostic factors. RESULTS: This cohort included 25 female and 53 male patients, with a mean age of 60.8 ± 11.4 years. Intrahepatic and extrahepatic cholangiocarcinoma were observed in 57 and 21 patients, respectively. First-line chemotherapy regimens were as follows: gemcitabine (n = 7), gemcitabine plus oxaliplatin (with or without cetuximab; n = 62) and 5FU plus cisplatin (n = 9). None of the patients achieved a complete response. The partial response rate was 35.9% (27/78), and the stable disease rate was 26.9% (21/78), giving a disease control rate of 62.8%. At the time of this analysis, with a median follow-up of 18 months, 13 patients were survivors. Median overall survival was 10 months [95% confidence interval (CI) 7-12], and median progression-free survival was 7 months (95% CI 6-8). Upon univariate analysis, only the distribution of the disease was significantly linked with prognosis, with a median overall survival of 10 months (95% CI 10-24) for solitary tumors versus 7 months (95% CI 6-11) in the case of infiltrative or multifocal tumors (p = 0.039). CONCLUSION: The disease control rate, overall survival and progression free-survival in this single-center retrospective study were in agreement with earlier reports. Specific features of this cohort were a large proportion of cholangiocarcinoma with associated cirrhosis (n = 30/78, 38.5%), mostly intrahepatic (n = 25/30, 83.5%). This confirms the increasing incidence of intrahepatic localization and the epidemiological link recently reported between intrahepatic biliary tract carcinoma and cirrhosis.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias dos Ductos Biliares/tratamento farmacológico , Ductos Biliares Intra-Hepáticos , Colangiocarcinoma/tratamento farmacológico , Adulto , Idoso , Neoplasias dos Ductos Biliares/mortalidade , Neoplasias dos Ductos Biliares/patologia , Colangiocarcinoma/mortalidade , Colangiocarcinoma/patologia , Cisplatino/administração & dosagem , Estudos de Coortes , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Feminino , Fluoruracila/administração & dosagem , Seguimentos , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Compostos Organoplatínicos/administração & dosagem , Oxaliplatina , Cuidados Paliativos , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida , Gencitabina
10.
Phys Rev Lett ; 106(20): 200601, 2011 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-21668211

RESUMO

We analyze the effect of a linear time variation of the interaction strength on a trapped one-dimensional Bose gas confined to an optical lattice. The evolution of different observables such as the experimentally accessible on site particle distribution are studied as a function of the ramp time by using time-dependent numerical techniques. We find that the dynamics of a trapped system typically displays two regimes: For long ramp times, the dynamics is governed by density redistribution, while at short ramp times, local dynamics dominates as the evolution is identical to that of an homogeneous system. In the homogeneous limit, we also discuss the nontrivial scaling of the energy absorbed with the ramp time.

11.
Clin Dermatol ; 39(2): 194-198, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34272008

RESUMO

Necrotizing infundibular crystalline folliculitis is a rare condition characterized by folliculocentric waxy papules in the seborrheic areas of adult patients, with intrafollicular filamentous birefringent crystalline deposits as the histopathologic clue. Although the real pathogenesis of necrotizing infundibular crystalline folliculitis remains unclear, the intrafollicular material seems to be derived from an interaction between such superficial microorganisms as gram-positive bacteria (Propionibacterium acnes, Staphylococcus spp), Malassezia yeasts, and sebaceous lipids. Topical or systemic antiacne agents or antimycotics appear to be effective therapy.


Assuntos
Foliculite , Malassezia , Adulto , Foliculite/diagnóstico , Foliculite/tratamento farmacológico , Humanos
12.
Soc Sci Med ; 245: 112702, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31835197

RESUMO

Neighbourhood resources are often considered to be spatially accessible to people when they are located close to their place of residence, a perspective which overlooks individuals' unique lived experience of their neighbourhood and how they define it. Drawing on the relational approach to place and on Sen's capability approach, we explore spatial accessibility to health-related resources, and the social gradient therein, in light of people's place experiences. Using data from 1101 young adults from Montreal (Canada) who participated in the Interdisciplinary Study of Inequalities in Smoking (ISIS), we compare the social gradients in the presence of health-related resources located (i) within uniform areas (defined as circular buffers and road-network buffers) around participants' place of residence; and (ii) within participants' self-defined neighbourhoods. Social inequalities in accessibility to a diversity of health-related resources (grocery stores, fruit and vegetable stores, eating and drinking places, recreational sports centres, civic, social, and fraternal organizations, bike paths, parks, social services, libraries, dental offices, physician offices) were more pronounced in self-defined neighbourhoods than in uniform buffer areas. Neglecting the variability in people's place experiences may distort the assessment of social inequalities in accessibility, and ultimately, of neighbourhood effects on health inequalities.


Assuntos
Ambiente Construído , Parques Recreativos , Características de Residência , Restaurantes , Fatores Socioeconômicos , Adulto , Comércio , Feminino , Humanos , Masculino , Quebeque , Adulto Jovem
13.
PLoS One ; 14(9): e0219276, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31560697

RESUMO

PCR inhibition is frequent in medical microbiology routine practice and may lead to false-negative results; however there is no consensus on how to detect it. Pathogen-specific and human gene amplifications are widely used to detect PCR inhibition. We aimed at comparing the value of PCR inhibitor detection using these two methods. We analysed Cp shifts (ΔCp) obtained from qPCRs targeting either the albumin gene or the pathogen-specific sequence used in two laboratory-developed microbiological qPCR assays. 3152 samples including various matrixes were included. Pathogen-specific amplification and albumin qPCR identified 62/3152 samples (2.0%), and 409/3152 (13.0%) samples, respectively, as inhibited. Only 16 samples were detected using both methods. In addition, the use of the Youden's index failed to determine adequate Cp thresholds for albumin qPCR, even when we distinguished among the different sample matrixes. qPCR targeting the albumin gene therefore appears not adequate to identify the presence of PCR inhibitors in microbiological PCR assays. Our data may be extrapolated to other heterologous targets and should discourage their use to assess the presence of PCR inhibition in microbiological PCR assays.


Assuntos
Amplificação de Genes , Técnicas Microbiológicas , Reação em Cadeia da Polimerase em Tempo Real , Humanos , Técnicas Microbiológicas/métodos , Técnicas Microbiológicas/normas , Pneumocystis/classificação , Pneumocystis/genética , Infecções por Pneumocystis/diagnóstico , Infecções por Pneumocystis/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase em Tempo Real/normas , Estudos Retrospectivos , Sensibilidade e Especificidade , Toxoplasma/classificação , Toxoplasma/genética , Toxoplasmose/diagnóstico , Toxoplasmose/microbiologia
14.
Int J Parasitol ; 48(9-10): 701-707, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29886198

RESUMO

The molecular diagnosis of toxoplasmosis lacks standardisation due to the use of numerous methods with variable performance. This diversity of methods also impairs robust performance comparisons between laboratories. The harmonisation of practices by diffusion of technical guidelines is a useful way to improve these performances. The knowledge of methods and practices used for this molecular diagnosis is an essential step to provide guidelines for Toxoplasma-PCR. In the present study, we aimed (i) to describe the methods and practices of Toxoplasma-PCR used by clinical microbiology laboratories in France and (ii) to propose technical guidelines to improve molecular diagnosis of toxoplasmosis. To do so, a yearly self-administered questionnaire-based survey was undertaken in proficient French laboratories from 2008 to 2015, and guidelines were proposed based on the results of those as well as previously published work. This period saw the progressive abandonment of conventional PCR methods, of Toxoplasma-PCR targeting the B1 gene and of the use of two concomitant molecular methods for this diagnosis. The diversity of practices persisted during the study, in spite of the increasing use of commercial kits such as PCR kits, DNA extraction controls and PCR inhibition controls. We also observed a tendency towards the automation of DNA extraction. The evolution of practices did not always go together with an improvement in those, as reported notably by the declining use of Uracil-DNA Glycosylase to avoid carry-over contamination. We here propose technical recommendations which correspond to items explored during the survey, with respect to DNA extraction, Toxoplasma-PCR and good PCR practices.


Assuntos
Testes Diagnósticos de Rotina/métodos , Guias como Assunto , Laboratórios/normas , Reação em Cadeia da Polimerase/métodos , Toxoplasma/isolamento & purificação , Animais , DNA de Protozoário/química , DNA de Protozoário/genética , Testes Diagnósticos de Rotina/normas , França , Humanos , Sensibilidade e Especificidade , Inquéritos e Questionários , Toxoplasma/genética
15.
Cancer Manag Res ; 10: 5537-5544, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30519101

RESUMO

BACKGROUND: Prognosis of metastatic non-small cell lung cancer significantly improved with the availability of checkpoint inhibitors (anti-PD-1/PD-L1). Unfortunately, reliable biomarkers to predict treatment benefit are lacking. PATIENTS AND METHODS: We prospectively collected clinical and laboratory data of 56 non-small cell lung cancer patients treated with a checkpoint inhibitor. The aim was to identify baseline parameters correlating with worse outcome and to create a risk score that enabled to stratify patients into different risk groups. As inflammation is known to promote tumor growth, we focused on inflammation markers in the blood. Disease control (DC) was defined as complete response, partial response, and stable disease on CT scan according to RECIST 1.1. RESULTS: Half of the patients achieved DC. Four parameters differed significantly between the DC group and the no disease control group: Eastern Cooperative Oncology Group performance status (P=0.009), number of organs with metastases (P=0.001), lactate dehydrogenase (P=0.029), and ferritin (P=0.005). A risk score defined as the number of these parameters (0= no risk factor) exceeding a threshold (Eastern Cooperative Oncology Group performance status ≥2, number of organs with metastases ≥4, lactate dehydrogenase ≥262U/L, and ferritin ≥241 µg/L) was associated with overall survival and progression-free survival. Overall survival at 6 and 12 months is as follows: Scores 0-1: 95% and 95%; Score 2: 67% and ≤33%; Scores 3-4: 15% and 0%. Progression-free survival at 6 and 12 months is as follows: Scores 0-1: 81% and 50%; Score 2: 25% and ≤25%; Scores 3-4: 0% and 0%. CONCLUSION: We propose an easy-to-apply risk score categorizing patients into different risk groups before treatment start with a PD-1/PD-L1 antibody.

16.
Am J Trop Med Hyg ; 98(6): 1727-1732, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29692312

RESUMO

In September 2014, an increase in the number of Cryptosporidium spp. gastrointestinal tract infections was reported over a 6-month period among children living in a remote area along the Maroni River in French Guiana. Children presented gastroenteritis symptoms with Cryptosporidium-positive stools. Questionnaires were administered and stool examinations were controlled 3 months after the onset of symptoms. Data collection included demographics, food consumption, river behavior, symptoms, and outcome. Stool specimens were tested using microscopy and polymerase chain reaction. Samples from the water systems were examined for turbidity and culture for bacteria. Data from the reference laboratory were analyzed to calculate the median cryptosporidiosis incidence among immunocompetent patients from 2008 to 2015. Data on gastroenteritis cases reported by the Delocalized Center for Prevention and Care in the area were also collected. We report a cluster of 14 cases. All cases were children, aged between 4.5 and 38 months. Seven reported moderate to severe dehydration and required hospitalization. Speciation and microbiological typing revealed the cluster strain was Cryptosporidium hominis subtype IbA10G2 but C. hominis IbA9G2 and IbA15G1 strains were also identified. The median incidence in French Guiana was 5.8 cases per year before the outbreak. The first cases of the cluster appeared in the dry season. We describe the clinical features, epidemiology, and state of current investigations for the largest documented outbreak of cryptosporidiosis in French Guiana.


Assuntos
Criptosporidiose/epidemiologia , Cryptosporidium/isolamento & purificação , Surtos de Doenças , Gastroenterite/epidemiologia , Pré-Escolar , Criptosporidiose/parasitologia , Cryptosporidium/genética , Demografia , Fezes/parasitologia , Feminino , Guiana Francesa/epidemiologia , Gastroenterite/parasitologia , Trato Gastrointestinal/parasitologia , Humanos , Imunocompetência , Lactente , Masculino , Reação em Cadeia da Polimerase , Rios , População Rural , Inquéritos e Questionários
17.
PLoS One ; 12(10): e0185668, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28982115

RESUMO

TLR4 is an innate immune receptor with expression in human skin, keratinocytes as well as squamous cell carcinoma (SCC) of the skin. In the present study we investigate the role of TLR4 as a negative regulator of keratinocyte proliferation. We present here that the expression of TLR4 increased with the differentiation of cultured keratinocytes in a passage-dependent manner or under calcium-rich conditions. Moreover, the down-regulation of TLR4 by specific knockdown increased the proliferation of HaCaT keratinocytes in vitro. In addition, subcutaneously injected HaCaT keratinocytes with shTLR4 formed growing tumors in nude mice. In contrast, we observed lower proliferation and increased migration in vitro of the SCC13 cell line stably overexpressing TLR4 in comparison to SCC13 TLR4 negative cells. In vivo, SCC13 TLR4-overexpressing tumors showed delayed growth in comparison to TLR4 negative tumors. The overexpression of TLR4 in SCC13 tumor cells was followed by phosphorylation of ERK1/2 and JNK and increased expression of ATF3. In gene expression arrays, the overexpression of TLR4 in tumor cells correlated with gene expression of ATF-3, IL-6, CDH13, CXCL-1 and TFPI. In summary, TLR4 negatively regulates the proliferation of keratinocytes and its overexpression reduces tumor growth of SCC cells.


Assuntos
Proliferação de Células/fisiologia , Queratinócitos/citologia , Receptor 4 Toll-Like/fisiologia , Fator 3 Ativador da Transcrição/metabolismo , Animais , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Linhagem Celular , Técnicas de Silenciamento de Genes , Humanos , Fatores Reguladores de Interferon/metabolismo , Camundongos , Camundongos Nus , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Receptor 4 Toll-Like/genética
18.
J Food Prot ; 69(9): 2084-90, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16995509

RESUMO

A temperature function integration technique that involves the calculation of the potential growth of Escherichia coli to obtain a process hygiene index (PHI) is the New Zealand industry standard method for assessing the potential for growth of enteric bacteria during meat cooling processes. The existing criteria to determine the acceptability of a cooling process with PHI values take no account of the differences between meat products and thus limit processing flexibility. A methodology was developed to set criteria for processing acceptability, based on the frequency distribution of the indicator organism E. coli number on meat carcasses immediately after slaughter (in log2 CFU per square centimeter) and a requirement that the E. coli numbers at the end of the cooling process be less than or equal to some maximum acceptable level. This methodology was used, along with accepted guidelines for maximum acceptable levels of E. coli in the meat and measured initial E. coli numbers for the whole New Zealand meat industry, to develop a set of PHI criteria that would be satisfied by a good-practice meat processing operation. A Monte Carlo modeling approach was used to illustrate the implications of these criteria if they had been applied to cooling processes for beef and lamb previously evaluated by the authors. If the proposed criteria were adopted, the maximum allowable PHI for beef cooling could be higher than that for lamb cooling because of the lower initial E. coli numbers found on beef than on lamb carcasses.


Assuntos
Escherichia coli/crescimento & desenvolvimento , Manipulação de Alimentos/métodos , Indústria de Processamento de Alimentos/normas , Higiene , Carne/microbiologia , Temperatura , Animais , Bovinos , Contagem de Colônia Microbiana , Carne/normas , Método de Monte Carlo , Nova Zelândia , Ovinos , Especificidade da Espécie
19.
Meat Sci ; 62(1): 93-106, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22061197

RESUMO

The effects of eight different pre-slaughter diets on gut microflora, pH and dry matter were evaluated in 112 slaughter-weight, pasture-finished heifers. Hide dirtiness at slaughter, plasma cortisol, meat pH and stickiness, and liveweight loss, were also examined. The pre-slaughter diets were: 48 h of 100% meadow hay, lucerne hay, red clover hay, perennial ryegrass hay, haylage, haylage supplemented with maize silage, pasture, or 24 h fasting before transport. Fasted animals had the highest counts of rumen Escherichia coli and Enterobacteria compared to other treatments (P<0.001), while red clover hay and haylage had the lowest (P<0.05). Faecal E. coli counts were also highest for fasted animals (P<0.05). Rumen E. coli and Enterobacteria counts were positively correlated with rumen pH (P<0.001), and negatively correlated with fibre intake (P<0.001). Diet significantly affected the pH of both the rumen and faeces (P<0.001), with fasted animals having the highest rumen pH and haylage and red-clover hay-fed animals the lowest. Dry matter (%) of the rumen contents was also significantly affected by diet (P<0.001). The mean carcass weight of fed heifers was 5 kg heavier than that of the fasted heifers (P<0.05). A pH/volatile fatty acid (VFA) dependent mechanism is suggested as the major mode for E. coli suppression by feeds used in the study. Coumarins may have contributed to lower ruminal and faecal E. coli counts with E. coli counts negatively correlated with expected coumarin ingestion (P<0.01). Feeding pasture-fed cattle conserved herbaceous forages, in preference to fasting, before transport for slaughter may prove beneficial in reducing the risk of carcass contamination with E. coli and other bacteria of digesta and/or faecal origin, and in protecting carcass weight.

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