Linear, weakly nonlinear and fully nonlinear models for soft tissues: which ones provide the most reliable estimations of the stiffness?

Benign and malignant lesions in tissues or organs can be detected by elastographic investigations in which pathological regions are spotted from local alterations of the stiffness. As is known, the shear modulus provides a measure of the stiffness of an elastic material. Based on the classical theory of linear elasticity, an elastogram yields estimations of the linear shear modulus from measurements of the speed of small-amplitude transverse waves propagating in the medium tested. In this paper, we show that the estimation of the shear modulus can be improved significantly by employing the fourth-order weakly nonlinear theory of elasticity (FOE), and indicate how the stiffness can be assessed more precisely with the use of FOE. We discuss also why FOE provides more reliable results than the fully nonlinear theory of elasticity. This article is part of the theme issue 'The Ogden model of rubber mechanics: Fifty years of impact on nonlinear elasticity'.

Understanding the role of threading dislocations on 4H-SiC MOSFET breakdown under high temperature reverse bias stress.

The origin of dielectric breakdown was studied on 4H-SiC MOSFETs that failed after three months of high temperature reverse bias stress. A local inspection of the failed devices demonstrated the presence of a threading dislocation (TD) at the breakdown location. The nanoscale origin of the dielectric breakdown was highlighted with advanced high-spatial-resolution scanning probe microscopy (SPM) techniques. In particular, SPM revealed the conductive nature of the TD and a local increase of the minority carrier concentration close to the defect. Numerical simulations estimated a hole concentration 13 orders of magnitude larger than in the ideal 4H-SiC crystal. The hole injection in specific regions of the device explained the failure of the gate oxide under stress. In this way, the key role of the TD in the dielectric breakdown of 4H-SiC MOSFET was unambiguously demonstrated.

Potential role of the heat shock protein 90 (hsp90) in buffering mutations to favour cyclical parthenogenesis in the peach potato aphid Myzus persicae (Aphididae, Hemiptera).

Heat-shock proteins 90 (hsp90s) are a class of molecules able to stabilize a network of 'client' proteins that are involved in several processes. Furthermore, recent studies indicated that mutations in the hsp90-encoding gene induce a wide range of phenotypic abnormalities, which have been interpreted as an increased sensitivity of different developmental pathways to hidden/cryptic mutations. In order to verify the role of hsp90 in aphids, we amplified and sequenced the hsp90 gene in 17 lineages of the peach potato aphid Myzus persicae (Sulzer, 1776) looking for the presence of mutations. In particular, we compared lineages with different reproductive modes (obligate vs. cyclical parthenogenesis), propensity to develop winged females and karyotype stability. Differently from the cyclical parthenogenetic lineages that possessed functional hsp90 genes, the seven analysed asexual lineages showed severe mutations (including frameshift and non-sense mutations). In vivo functional assays with the hsp90-inhibitor geldanamycin showed that some lineages with cyclical parthenogenesis may lose their ability to induce sexuales in the absence of active hsp90 revealing the presence of cryptic mutations in their genomes. As a whole, our data suggest that hsp90 could play in aphids a role in buffering hidden/cryptic mutations that disrupt cyclical parthenogenesis.

Severe acute colitis related to levodopa treatment.

The first case of severe drug-induced gastrointestinal injury related to levodopa is described. The 86-year-old patient experienced acute colitis temporally related to the intake of the drug with complete resolution of symptoms on levodopa withdrawal. Awareness of the possibility of a levodopa-related damage on colon biopsies performed for acute colitis is of paramount importance for pathologists. However, in order to exclude or confirm a drug-related damage an effective communications between clinicians and pathologists is always required.

Pathologist's assistant (PathA) and his/her role in the surgical pathology department: a systematic review and a narrative synthesis.

In recent decades, various highly qualified individuals have increasingly performed tasks that have historically been handled by physicians with the aim of reducing their workload. Over time, however, these "physician assistants" or "physician extenders" have gained more and more responsibilities, showing that specific tasks can be performed equally skilfully by specialised health care professionals. The pathologist's assistant (PathA) is a highly qualified technician who works alongside the pathologist and is responsible for the grossing and autopsies. This profession was developed in the USA, with formal training programmes starting in 1970 when Dr. Kinney, director of the Department of Pathology of Duke University, Durham, NC, started the first dedicated course. Most institutes in the USA and Canada currently employ these technical personnel for grossing, and numerous papers published over the years demonstrate the quality of the assistance provided by the PathA, which is equal to or sometimes even better than the performance of pathologists. The PathA can be employed to carry out a wide range of tasks to assist the pathologist, such as grossing (the description and reduction of surgical specimens), judicial autopsies and administrative and supervisory practices within the laboratory or assistance in research, although the diagnosis is always the pathologist's responsibility. Since this role has already been consolidated in North America, part of the relevant literature is altogether out of date. However, the situation is different in Europe, where there is an increasing interest in PathA, mainly because of the benefits of their inclusion in anatomic pathology laboratories. In the UK, biomedical scientists (BMS, the British equivalent of PathA) are involved in many tasks both in surgical pathology and in cytopathology, which are generally performed by medically trained staff. Several papers have been recently published to highlight the role of BMS with the broader public. This report aimed to conduct a systematic review of all the articles published about the PathA/BMS and to perform a narrative synthesis. The results may contribute to the evidence for including the PAthA/BMS within a surgical pathology laboratory organisation.

Development and validation of a novel SNP panel for the genetic characterization of Italian chicken breeds by next-generation sequencing discovery and array genotyping.

The aim of this study was to compare the intra and inter genetic variability and population structure of 7 indigenous chicken breeds of the Veneto region, through a novel panel of 64 SNP, each located in an exonic region and mostly on different chromosomes. A total of 753 blood samples from 7 local chicken breeds (Ermellinata di Rovigo, Millefiori di Lonigo, Polverara, Pepòi, Robusta Lionata, Robusta Maculata, and Padovana) was collected and analyzed. Two strains of Polverara (Nera and Bianca) and Padovana (Dorata and Camosciata) were included in the study. The observed heterozygosity ranged from 0.124 (Pèpoi) to 0.244 (Ermellinata di Rovigo), and the expected heterozygosity varied from 0.132 (Millefiori di Lonigo) to 0.300 (Ermellinata di Rovigo). Global FIS results (0.114) indicated a low-medium inbreeding effect, with values ranging from 0.008 (Millefiori di Lonigo) to 0.223 (Ermellinata di Rovigo). Pairwise FST values (0.167) for all populations ranged from 0.020 (Polverara Nera and Polverara Bianca) to 0.193 (Robusta Lionata and Polverara Nera), indicating that the studied breeds were genetically highly differentiated. The software STRUCTURE was used to detect the presence of population substructures, and the most probable number of clusters (K) of the 10 chicken populations was at K = 8. The affiliation was successful in all Veneto chicken breeds. The present SNP marker results, compared with previous data obtained using microsatellites, provided a reliable estimate of genetic diversity within and between the studied breeds, and demonstrated the utility of the proposed panel as a rapid, efficient, and cost-effective tool for periodical monitoring of the genetic variability among poultry populations. In addition, the present SNP panel could represent a resource for a systematic approach with relevant impact on breeding program decisions and could turn out to be a reliable tool for genetic traceability of indigenous chicken meat. Adoption of a periodical monitoring system of genetic diversity is a fundamental tool in conservation actions and should increase the value of typical and niche products.

Bladder tissue biomechanical behavior: Experimental tests and constitutive formulation.

A procedure for the constitutive analysis of bladder tissues mechanical behavior is provided, by using a coupled experimental and computational approach. The first step pertains to the design and development of mechanical tests on specimens from porcine bladders. The bladders have been harvested, and the specimens have been subjected to uniaxial cyclic tests at different strain rates along preferential directions, considering the distribution of tissue fibrous components. Experimental results showed the anisotropic, non-linear and time-dependent stress-strain behavior, due to tissue conformation with fibers distributed along preferential directions and their interaction phenomena with ground substance. In detail, experimental data showed a greater tissue stiffness along transversal direction. Viscous behavior was assessed by strain rate dependence of stress-strain curves and hysteretic phenomena. The second step pertains the development of a specific fiber-reinforced visco-hyperelastic constitutive model, in the light of bladder tissues structural conformation and experimental results. Constitutive parameters have been identified by minimizing the discrepancy between model and experimental data. The agreement between experimental and model results represent a term for evaluating the reliability of the constitutive models by means of the proposed operational procedure.

Recognition and management of delirium among doctors, nurses, physiotherapists, and psychologists: an Italian survey.

BACKGROUND: There are no studies that have identified the ability to recognize and manage delirium among Italian health providers caring for patients at risk. Therefore, the Italian Association of Psychogeriatrics (AIP) conducted a multicenter survey among doctors, nurses, psychologists and physiotherapists to assess their competence regarding the theme of delirium and its management in the everyday clinical practice. METHODS: The survey period was 1st June 2013 to 30th November 2013. The invitation to participate was sent via email, with publication on the AIP website. The survey included 14 questions and two case vignettes. RESULTS: A total of 648/1,500 responses were collected. Most responders were doctors (n = 322/800), followed by nurses (n = 225/500), psychologists (n = 51/100), and physiotherapists (n = 30/100). Generally, doctors and psychologists correctly defined delirium, while nurses and physiotherapists did not. The most frequently used diagnostic tools were the Confusion Assessment Method (CAM) and the Diagnostic and Statistical Manual of Mental Disorders-IV. Delirium intensity was rarely assessed. Hypoactive delirium was generally managed with non-pharmacological approaches, while hyperactive delirium with a combination of non-pharmacological and pharmacological approaches. However, possible causes of delirium were under-assessed by half of doctors and by the majority of other professionals. Nurses, psychologists and physiotherapists did not answer the case vignettes, while doctors identified the correct answer in most cases. CONCLUSIONS: This is the first Italian survey among health providers caring for patients at risk of delirium. This is also the first survey including doctors, nurses, psychologists and physiotherapists. The results emphasize the importance of training to improve knowledge of this relevant unmet medical need.

Evaluation of the HB&L System for the Microbiological Screening of Storage Medium for Organ-Cultured Corneas.

Aims. To compare HB&L and BACTEC systems for detecting the microorganisms contaminating the corneal storage liquid preserved at 31°C. Methods. Human donor corneas were stored at 4°C followed by preservation at 31°C. Samples of the storage medium were inoculated in BACTEC Peds Plus/F (aerobic microorganisms), BACTEC Plus Anaerobic/F (anaerobic microorganisms), and HB&L bottles. The tests were performed (a) after six days of storage, (b) end of storage, and (c) after 24 hours of preservation in deturgescent liquid sequentially. 10,655 storage and deturgescent media samples were subjected to microbiological control using BACTEC (6-day incubation) and HB&L (24-hour incubation) systems simultaneously. BACTEC positive/negative refers to both/either aerobic and anaerobic positives/negatives, whereas HB&L can only detect the aerobic microbes, and therefore the positives/negatives depend on the presence/absence of aerobic microorganisms. Results. 147 (1.38%) samples were identified positive with at least one of the two methods. 127 samples (134 identified microorganisms) were positive with both HB&L and BACTEC. 14 HB&L+/BACTEC- and 6 BACTEC+/HB&L- were identified. Sensitivity (95.5%), specificity (99.8%), and positive (90.1%) and negative predictive values (99.9%) were high with HB&L considering a 3.5% annual contamination rate. Conclusion. HB&L is a rapid system for detecting microorganisms in corneal storage medium in addition to the existing methods.

Fecal progestins during pregnancy and postpartum periods of captive red brocket deer (Mazama americana).

This study aimed to validate the enzyme immunoassay (EIA) for fecal progestin quantification of the species Mazama americana, define its excretion profile during periods of gestation and postpartum and determine the gestation period and resumption of postpartum ovarian activity in this species in captivity. Fecal samples were collected twice a week during gestation and every day in the postpartum period, and analyzed using EIA. The mean concentrations (±SEM) of fecal progestins during gestation were 2180.0±299.1ng/g in early pregnancy (week 1-11), 3271.4±406.9ng/g in middle pregnancy (week 12-22) and 5592.0±1125.8ng/g in late pregnancy (week 23-32). The gestation period determined for the species was 220.9±1.2 days. The concentration of progestins reached its peak prior to parturition and returned to baseline levels in 4±0.31 days after parturition. In the postpartum period, the mean concentrations of fecal progestins were 1564.2±182.6ng/g in the interval between parturition and resumption of ovarian activity, 469.8±24.5ng/g in the inter-luteal phase and 2401.7±318.5ng/g during the luteal phase, such that the postpartum period and the luteal phase differed from the inter-luteal phase. Fecal progestin profiling permitted the detection of ovulation 26.9±3.4 days after parturition in all the hinds studied and estimation of the mean duration of the estrous cycle, 21.3±1.1 days. Analysis established that concentrations of progestins above 3038.76ng/g diagnosed pregnancy, a value determined from the week 12 of gestation. Moreover, the quantification of fecal progestins by EIA proved to be an important tool for noninvasive endocrine monitoring and to obtain reproductive data on the species M. americana in captivity.

Insulin production and resistance in cystic fibrosis: effect of age, disease activity, and genotype.

AIM: To assess the major determinants of glucose tolerance between age, genotype, and clinical status in cystic fibrosis (CF) patients, and study if defects of insulin secretion and insulin sensitivity were associated with the onset of CF-related diabetes (CFRD). SUBJECTS AND METHODS: One hundred and nineteen patients, in stable clinical condition were studied. They were subdivided into 3 groups based on age, and 2 groups based on Schwachman-Kulczycki clinical score. All patients were genotyped, and subsequently divided into 3 groups. Ninety-four healthy normal-weight controls, comparable for sex and age were also studied. All subjects had baseline blood samples taken for glucose and insulin, C-peptide, and glycated hemoglobin. Homeostasis model assessment of insulin resistance (HOMA-IR), fasting glucose/insulin ratio (FGIR) were calculated as indices of IR and insulinogenic index as a marker of pancreatic ß-cell function. All patients underwent an oral glucose tolerance test, and 57 underwent an IVGTT for the calculation of first-phase (FPIR) and acute insulin responses (AIR). RESULTS: The F508del homozygous patients had an increased chance of developing impaired glucose tolerance (IGT) and significantly lower FPIR, decreased HOMA-IR, and insulinogenic index. Heterozygote F508del patients had an increased chance of having normal glucose tolerance. HOMA-IR, FGIR, and insulinogenic index did not change with age or clinical score. HOMAIR correlated with FPIR. FPIR correlated positively with insulinogenic index. AIR correlated negatively with FGIR, and positively with C-reactive protein. In multiple linear regression analyses, glucose tolerance was related to the agegroup, and to the HOMA-IR and insulinogenic indexes. CONCLUSIONS: IGT and CFRD were related mainly to genotype, although, as expected, the prevalence increased with age. The data suggested a possible combined contribution of insulin deficiency, ß-cell function, and reduced insulin sensitivity to the onset of CFRD; however, further studies are warranted to better elucidate this aspect.

ß-HHVs and HHV-8 in Lymphoproliferative Disorders.

Similarly to Epstein-Barr virus (EBV), the human herpesvirus-8 (HHV-8) is a γ-herpesvirus, recently recognized to be associated with the occurrence of rare B cell lymphomas and atypical lymphoproliferations, especially in the human immunodeficiency virus (HIV) infected subjects. Moreover, the human herpesvirus-6 (HHV-6), a ß-herpesvirus, has been shown to be implicated in some non-malignant lymph node proliferations, such as the Rosai Dorfman disease, and in a proportion of Hodgkin's lymphoma cases. HHV-6 has a wide cellular tropism and it might play a role in the pathogenesis of a wide variety of human diseases, but given its ubiquity, disease associations are difficult to prove and its role in hematological malignancies is still controversial. The involvement of another ß-herpesvirus, the human cytomegalovirus (HCMV), has not yet been proven in human cancer, even though recent findings have suggested its potential role in the development of CD4(+) large granular lymphocyte (LGL) lymphocytosis. Here, we review the current knowledge on the pathogenetic role of HHV-8 and human ß-herpesviruses in human lymphoproliferative disorders.

Variation of genetic diversity over time in local Italian chicken breeds undergoing in situ conservation.

The aim of this study was to analyze the variation of different genetic diversity measures in 5 Italian local chicken breeds over a 4-yr period of conservation. The local breeds were Ermellinata di Rovigo, Padovana, Pépoi, Robusta Lionata, and Robusta Maculata. A total of 368 samples were chosen for the analysis among the birds hatched in the years 2002 and 2006. Genetic variation over 30 microsatellite loci was analyzed. All 30 microsatellites were polymorphic, with a total number of alleles equal to 251, a mean (±SD) of 8.367 ± 3.378 across populations and 3.233 ± 1.338 within population. After 4 yr of conservation, a loss of alleles occurred for all the microsatellites, with the exception of 4 loci. The total number of alleles and expected heterozygosity estimates significantly decreased during the 4 yr of conservation, whereas no significant differences were detected for the microsatellites polymorphism information content or for the observed heterozygosity estimates. A decrease of the inbreeding coefficient occurred for all the breeds, with the exception of Padovana and Robusta Lionata. All populations showed evidence of a persistent significant deviation from Hardy-Weinberg equilibrium caused by an excess of homozygotes, except Robusta Maculata, which reached the equilibrium in 2006. For Pépoi, Padovana, Ermellinata di Rovigo, and Robusta Maculata, molecular coancestry increased significantly (P < 0.001) after the 4 yr of conservation. No evident genetic structures were detectable within breed, both for 2002 and for 2006 individuals. However, a slight increase in the proportion of membership for each breed had occurred in the year 2006 compared with the data obtained in the year 2002. As consequence, within breed, individuals in 2006 appear more homogeneous, producing clearer, more distinctive and separated groups. Molecular markers analysis helped us monitor the genetic variability of local breeds involved in a conservation scheme, enabling the planning of new strategies for the improvement of in situ conservation schemes.

Feasibility of the direct application of near-infrared reflectance spectroscopy on intact chicken breasts to predict meat color and physical traits.

Physical and color characteristics of chicken meat were investigated on 193 animals by directly applying a fiberoptic probe to the breast muscle and using the visible-near-infrared (NIR) spectral range from 350 to 1,800 nm. Data on pH was recorded 48 h postmortem (pH); lightness (L*), redness (a*), and yellowness (b*) 48 h postmortem; thawing and cooking losses and shear force after freezing. Partial least squares regressions were performed using untreated data, raw absorbance data (log(1/R)), and multiplicative scatter correction plus first or second derivative spectra. Models were validated using full cross-validation, and their predictive ability was determined by root mean square error of cross-validation (RMSE(CV)) and correlation coefficient of cross-validation (r(cv)). Means (±SD) of pH, L*, a*, b*, thawing loss, cooking loss, and shear force were 5.83 ± 0.13, 44.54 ± 2.42, -1.90 ± 0.62, 3.21 ± 3.28, 4.84 ± 2.44%, 19.39 ± 2.95%, and 16.08 ± 3.83 N, respectively. The best prediction models were developed using log(1/R) spectra for b* (r(cv) = 0.93; RMSE(CV) = 1.16) and a* (r(cv) = 0.88; RMSE(CV) = 0.29), while a medium predictive ability of NIR was obtained for pH, L*, and thawing and cooking losses (r(cv) from 0.69 to 0.76; RMSE(CV) from 0.01 to 1.73). Finally, predicted model for shear force (r(cv) = 0.41; RMSE(CV) = 3.18) was unsatisfactory. Results suggest that NIR is a feasible technique for the assessment of several quality traits of intact breast muscle.

Protein kinase C modulates NMDA receptors in the myenteric plexus of the guinea pig ileum during in vitro ischemia and reperfusion.

BACKGROUND: Ischemic episodes lead to profound functional and structural alterations of the gastrointestinal tract which may contribute to disorders of intestinal motility. Enhancement of glutamate overflow and the consequent activation of NMDA (N-methyl-D-aspartate) receptors may participate to such changes by modulating different enteric neurotransmitter systems, including cholinergic motor pathways. METHODS: The molecular mechanism/s underlying activation of NMDA receptors in the guinea pig ileum were investigated after glucose/oxygen deprivation (in vitro ischemia) and during reperfusion. KEY RESULTS: The number of ileal myenteric neurons positive for NR1, the functional subunit of NMDA receptors, and its mRNA levels were unchanged after in vitro ischemia/reperfusion. In these conditions, the protein levels of NR1, and of its phosphorylated form by protein kinase C (PKC), significantly increased in myenteric neurons, whereas, the levels of NR1 phosphorylated by protein kinase A (PKA) did not change, with respect to control values. Spontaneous glutamate overflow increased during in vitro ischemia/reperfusion. In these conditions, the NMDA receptor antagonists, D(-)-2-amino-5-phosphonopentanoic acid [(D)-AP5] (10 µmol L(-1)) and 5,7-dichlorokynurenic acid (5,7-diClKyn acid) (10 µmol L(-1)) and the PKC antagonist, chelerythrine (1 µmol L(-1)), but not the PKA antagonist, H-89 (1 µmol L(-1)), were able to significantly depress the increased glutamate efflux. CONCLUSIONS & INFERENCES: The present data suggest that in the guinea pig ileum during in vitro ischemia/reperfusion, NR1 protein levels increase. Such event may rely upon posttranscriptional events involving NR1 phosphorylation by PKC. Increased NR1 levels may, at least in part, explain the ability of NMDA receptors to modulate a positive feedback on ischemia/reperfusion-induced glutamate overflow.

Avaliação da dosagem de própolis pulverizada nas folhas de amoreira (morus sp.) sobre o desenvolvimento biológico e produtivo do bicho-da-seda (bombyx mori L. ) / Evaluación de la dosis de propóleos esparcidas en las hojas de morera (morus sp.) en el desarrollo biológico y productivo del gusano de seda (bombyx mori L.) / Evaluation of the doses of propolis pulverization in mulberry leaves (morus sp.) on the biological and productive development of silkworm (bombyx mori L.)

Este experimento foi realizado no Laboratório de Sericicultura, no Campus Sede da Universidade Paranaense (UNIPAR) de Umuarama, no período de 17/09/2009 a 17/10/2009, com o objetivo de verificar o efeito da própolis em diferentes dosagens na alimentação durante o desenvolvimento biológico do bicho-da-seda (Bombxy mori L). O método empregado na parte experimental foi a pulverização do extrato alcoólico de própolis, diluído em 500 mL de água destilada nas folhas de amoreira, nas seguintes dosagens, água-controle, 5mL, 10mL, 15mL e 20mL compondo os tratamentos T1, T2, T3, T4, T5, respectivamente. As folhas de amoreira foram fornecidas cinco vezes ao dia, durante o manejo alimentar. Verificou-se pelos resultados obtidos, que as diferentes dosagens de própolis utilizadas interferem no ganho de peso das lagartas, no peso dos casulos verdes e crisálidas quando comparado ao tratamento controle, influenciando também no número de casulos formados e, para os teores de seda bruto e líquido não apresentaram resultados significativos, quando comparados com o tratamento controle. Portanto, verificou-se que a própolis, nas dosagens utilizadas, não trouxe efeitos depressivos à biologia e produção do bicho-da-seda.

This experiment was conducted at the Sericulture Laboratory, in the Campus Sede of the Universidade Paranaense (UNIPAR) in Umuarama, from 17/09/2009 to 17/10/2009, in order to verify the effects of propolis in different dosages during the development of silkworm (Bombyx mori L). The method used during the experiment was the dillution of an alcohoolic solution of propolis, in 500 mL of destilled water with its further pulverization on mullberry leaves, with the following doses: water control; 5 mL; 10 mL; 15 mL; 20 mL, composing the following treatments: T1, T2, T3, T4, T5, respectively. The mullberry leaves were sprinkled five times a day, during the feed management. It was verified by the results that the different doses of propolis used interfere with gain-weight of the larvae, weight of cocoons and chrysalis, when compared to control. The treatment also influenced the number of cocoons formed. The contento fraw and liquid silk were not significant when compared with the control. Therefore, it was concluded that the propolis, used in those dosages, brought no depressive effects to the development and the production of silkworm.

Este experimento se realizó en el Laboratorio de Sericicultura del Campus Sede de la Universidad Paranaense (UNIPAR) de Umuarama, en el período de 17/09/2009 a 17/10/2009, con el objetivo de verificar el efecto de propóleos en diferentes dosis en la alimentación durante el desarrollo biológico del gusano de seda (Bombyx mori L.). El método usado en la parte experimental fue la pulverización del extracto alcohólico de propóleos, diluido en 500 ml de agua destilada en las hojas de morera, en las siguientes dosis: agua control, 5 ml, 10 ml, 15 ml y 20 ml componiendo los tratamientos T1, T2, T3, T4, T5, respectivamente. Las hojas de morera fueron suministradas cinco veces al día, durante el manejo alimentar. Por los resultados obtenidos se verificó que las dosis diferentes de propóleos utilizadas interfieren en el gano de peso de los gusanos, en el peso de los capullos verdes y crisálidas cuando comparado al tratamiento control, influenciando también en el número de capullos formados y, para contenidos de seda bruta y líquida no presentan resultados significativos, mientras comparado con el tratamiento control. Sin embargo, se puede verificar que propóleos, en dosis utilizadas, no trajo efectos depresivos a la biología y producción del gusano.

Carcase characteristics and qualitative meat traits of three Italian local chicken breeds.

1. An experiment involving 60 male chickens reared in an organic production system was carried out in order to investigate carcase characteristics and qualitative meat traits of three slow-growing Italian local breeds of chicken (Ermellinata, Padovana and Pepoi). 2. Chicks were randomly selected at hatch, raised together under the same conditions, slaughtered at 190 d of age, dissected for carcase traits, and meat (breast and thigh) stored for subsequent analysis of quality parameters. 3. Ermellinata (EA) chickens were significantly different from Padovana (PA) and Pepoi (PI) chickens for live, carcase and thigh weights. Breeds were also different for breast muscle protein content (EA > PI and PA), shear force (PA < EA and PI) and cooking loss (PI > PA and EA) values. 4. The CIE system values of lightness (L*), redness (a*), and yellowness (b*) evidenced a distinctive darker meat and lighter skin colour of PA breast meat. 5. Polyunsaturated fatty acids composition of breast meat was similar among the analysed breeds. EA had significantly higher saturated but significantly lower monounsaturated fatty acid contents than the other two breeds.

Genetic characterization of local Italian breeds of chickens undergoing in situ conservation.

The objectives of this study were to determine genetic variation and to analyze population structure of 6 Italian local chicken breeds involved in a conservation program. Twenty microsatellite markers were investigated in 337 birds belonging to 6 breeds: Ermellinata di Rovigo, Robusta Maculata, Robusta Lionata, Pépoi, Padovana, and Polverara; a commercial layer cross was used as reference. One hundred twelve alleles were detected in the overall population, with a mean number of 5.6 +/- 2.1 alleles per locus. For the local breeds, the observed and expected heterozygosity ranged from a minimum of 0.240 to a maximum of 0.413 and from 0.243 to 0.463 for the Pépoi and Polverara breeds, respectively. Deviation from Hardy-Weinberg equilibrium was observed in 5 breeds and in the commercial cross. The overall population heterozygote deficiency was 0.427, the average inbreeding coefficient was 0.097, and the heterozygote deficiency due to breed subdivisions was 0.437. Reynolds' distances were used to draw an unrooted neighbor-joining tree, which topology gave information on the genetic origin of these breeds and confirmed their known history. The estimated molecular kinship within a breed ranged from 0.559 to 0.769, evidencing high coancestry. Structure analysis was performed to detect the presence of population substructures. Inferred clusters corresponded to the different breeds, without presence of admixture. The exception was the Polverara breed, for which a more complex genetic structure was found. The results supported the decision of safeguarding these breeds as an important reservoir of genetic diversity and confirmed the usefulness of microsatellite markers to characterize and to monitor genetic variability in local chicken breeds.