Fluorescence of Extracts from Argentine Hake (Merluccius hubbsi) Muscle and Its Correlation with Quality Indices During Chilled Storage

Argentine hake (Merluccius hubbsi) was stored chilled for 8 days. The evolution of fluorescence of the aqueous and organic extracts of muscle during storage at 4°C was studied and correlated with common damage indices; pH, total volatile basic nitrogen, free fatty acids, and the fluorescence intensity of the aqueous phase showed a good correlation with storage time. The excitation-emission matrices of the aqueous extracts were also obtained. A fluorescence landscape that could be attributed to tryptophan decreased with storage time, meanwhile a peak (around 340 and 400 nm for excitation and emission wavelengths, respectively) is developed during chilled storage.     

Sorghum Pasta and Noodles: Technological and Nutritional Aspects

Plant Foods for Human Nutrition - Sorghum is a major cereal crop with various agronomic advantages, contains health-promoting compounds and is gluten-free. There is a growing tendency to use...     

A KCNJ10 mutation previously identified in the Russell group of terriers also occurs in Smooth-Haired Fox Terriers with hereditary ataxia and in related breeds

Background

Hereditary ataxias with similar phenotypes were reported in the Smooth-Haired Fox Terrier, the Jack Russell Terrier and the Parson Russell Terrier. However, segregation analyses showed differing inheritance modes in these breeds. Recently, molecular genetic studies on the Russell group of terriers found independent mutations in KCNJ10 and CAPN1, each associated with a specific clinical subtype of inherited ataxia. The aim of this study was to clarify whether or not Smooth-Haired Fox Terriers with hereditary ataxia and dogs of other related breeds harbor either of the same mutations. A sub goal was to update the results of KCNJ10 genotyping in Russell group terriers.

Findings

Three Smooth-Haired Fox Terriers with hereditary ataxia and two Toy Fox Terriers with a similar phenotype were all homozygous for the KCNJ10 mutation. The same mutation was also found in a heterozygous state in clinically unaffected Tenterfield Terriers (n = 5) and, in agreement with previous studies, in Jack Russell Terriers, Parson Russell Terriers, and Russell Terriers.

Conclusions

A KCNJ10 mutation, previously associated with an autosomal recessive spinocerebellar ataxia in Jack Russell Terriers, Parson Russell Terriers, and Russell Terriers segregates in at least three more breeds descended from British hunting terriers. Ataxic members of two of these breeds, the Smooth-Haired Fox Terrier and the Toy Fox Terrier, were homozygous for the mutation, strengthening the likelihood that this genetic defect is indeed the causative mutation for the disease known as “hereditary ataxia” in Fox Terriers and “spinocerebellar ataxia with myokymia, seizures or both” in the Russell group of terriers.     

Shoot development and dieback in progenies of Nothofagus obliqua

Shoot growth and dieback were compared among progenies of nursery-grown seedlings of Nothofagus obliqua belonging to seven progenies of the same provenance (Quila-Quina, Argentina). First-year shoots consisted of one growth unit (GU) and second-year shoots of one or two GUs. The probability of development of two GU was similar for all progenies. Progenies were different in terms of shoot size, terminal bud abscission, the extent of shoot dieback after shoot extension and the node of origin of the relay shoot on the first shoot. Plants with a second-year shoot consisting of two GUs had a thicker stem and more nodes than those with single-GU shoots. The selection of N. obliqua seed trees based on architectural traits suitable for forestry development at specific sites must contemplate variability among progenies and their probabilities of successful development under different conditions.     

Changes in understory species diversity during theNothofagus pumilio forest management cycle

Human commercial activities must be compatible with sustainable management to achieve species conservation in the natural environment. After harvesting, diversity and abundance of understory species differ substantially from the pre-harvest situation. Have knowledge of the changes that logging produces in all components of the system allows us to develop management alternatives with reduced impacts. The objective of this work was to evaluate changes in density, biomass and diversity of understory species along a forest shelterwood cut system management cycle in aNothofagus pumilio forest. Six forest management situations (postharvesting stands and different phases of forest development) were sampled in a pureN. pumilio forest of Tierra del Fuego (Argentina) of middle-high site class (fromclass I toIII). Species number, density and biomass were modified substantially after a shelterwood cut. These were being greatest after cutting and falling substantially when the forest canopy closes during theinitial growth phase, returning to values similar to this virgin forest when themature phase was reached. The impact of the forest management on understory species diversity is analyzed and discussed. The silvicultural practices applied toN. pumilio forest in Tierra del Fuego permit the introduction of alien flora to the system, and produce great changes during the forest management cycle. To Celina Matteri, Itatí Ferraro, and Rosa Kofalt for their aid in taxonomical identification. To Juan Manuel Cellini, Ricardo Vukasovic and Gregorio Martínez Pastur for their participation in the field work; and to the sawmillLos Castores, Universidad Nacional de la Patagonia Austral, Centro Austral de Investigaciones Científicas and Instituto Nacional de Tecnología Agropecuaria for the institutional and financial support.     

Performance assessment of small irrigation schemes along the Mauritanian banks of the Senegal River

Irrigation plays a fundamental role in world food provision but, to date, it has performed below expectations in Sub-Saharan Africa. The present study assesses and diagnoses the performance of 22 small and medium size community-managed irrigation schemes, mainly devoted to rice production, in different locations along the Mauritanian banks of the Lower Senegal River. The evaluations followed the Rapid Appraisal Process in which semi-structured interviews were held with representatives of the Cooperatives’ Boards in charge of each scheme to obtain information about the organisation of the cooperative, land tenure, irrigation system and organization, cropping pattern and soils. Additionally, for each irrigation scheme, the water-delivery service was characterized by making qualitative and comparative observations during field inspections; the pumping station's performance was diagnosed by a local specialist; the discharge at the head of the system was measured; daily irrigation time was recorded; and crop yields were determined by plot sampling. Then a set of performance indicators was computed. Water delivery capacity referred to irrigated areas was insufficient in a third of the schemes, and this insufficiency was exacerbated by poor maintenance. Irrigation intensity in habilitated areas was rather low being less than 0.66 in 50% of the schemes. The average productivity of land, irrigation water, and fuel (3.38 t ha⁻¹, 0.30 kg m⁻³ and 2.37 kg kWh⁻¹, respectively) were well below potential.     

A comparison of soil- and canopy temperature-based methods for the early detection of water stress in a simulated patch of pasture

This paper evaluates the sensitivity of two different methods of water stress detection in a simulated patch of pasture grown in a greenhouse. The performance of two indices, based respectively on canopy temperature and soil water content values — the latter gauged by means of a time domain reflectometry (TDR) system, was assessed against actual evapotranspiration, measured by a very accurate weighing system. Both methods were able to detect water shortage by the time transpiration was reduced to some 80% of its potential value. The soil-based index, however, relied on the estimate of root water extraction rate, which may not be known. It is concluded that detection of water shortage by means of a canopy temperature-based stress index is to be preferred to measuring soil water deficits by time domain reflectometry, despite the accuracy of the TDR-based soil water content estimate.     

Fine-Scale Spatial Genetic Structure in Perennial Grasses in Three Environments

Past research has shown that changes in grazing-resistance traits may be associated with genetic changes in plant populations. Little is known about spatial genetic relationships within plant populations (spatial genetic structure) and any grazing effects on these relationships. Here we present observations of the fine-scale spatial genetic structure in three grass species in semiarid environments (Arizona, Mexico, and Argentina). In each environment, populations of a dominant grass species were sampled from two sites with contrasting livestock grazing histories. Plant genotypes were described with the use of amplified fragment length polymorphism markers. In Arizona, populations of sideoats grama (Bouteloua curtipendula var. caespitosa Gould and Kapadia) differed in that one has never experienced livestock grazing, whereas cattle have grazed the other. In the other two environments, populations exposed to long-term heavy grazing were examined, along with those that experienced either moderate grazing (Mexico, blue grama [Bouteloua gracilis {Willd. ex Kunt} Lag. ex Griffiths]) or extended exclusion of livestock (Argentina [Poa ligularis Nees ex Steud.]). Based on independent analysis of each population, we observed no differences in average gene diversity between populations of each species. With the use of analysis of molecular variance we found slight but significant genetic differentiation between populations with different grazing histories in Arizona and Argentina. Significant genetic structure was present in all populations and indicated an inverse relationship between spatial and genetic distance. Interestingly, this relationship was most pronounced in the cattle-free sideoats grama population, suggesting larger genetic neighborhood areas in the absence of livestock. Less distinct differences in spatial genetic structure associated with grazing history were evident in the other two species. We hypothesize that livestock grazing may lead to increased homogeneity in genetic structure at the landscape scale. Effectively examining this hypothesis presents many experimental challenges.     

The expression pattern of TIR8 is conserved among vertebrates

IL-1R/TLRs play an important role in the inflammatory responses. Their signaling pathway is tightly regulated to keep inflammation under control. The regulation involves both extracellular and intracellular mechanisms. TIR8, also known as SIGIRR (Single Immunoglobulin IL-1R-Related molecule), is an orphan receptor belonging to the IL-1R/TLRs super-family. Recent studies suggest its role in modulating the inflammatory response in the gastrointestinal tract in mice, acting as an IL-1 receptor family antagonist. We identified the sequence and analyzed the expression of TIR8 in a wide panel of organs and tissues in different animals. There was high homology of the cDNA sequence among human, mouse and the domestic species (74–85%). The pattern of expression of this receptor was similar in all the species examined (high levels in kidney and gastrointestinal tract) and similar to the human. These results demonstrate that TIR8 is conserved, in evolutionary terms, both with regard to sequence and pattern of expression, a finding consistent with a key function of this molecule in modulating inflammation in the gastrointestinal tract.     

Validation of a multiplex PCR assay to detect Babesia spp. and Anaplasma marginale in cattle in Uruguay in the absence of a gold standard test

Detection of bovine Babesia spp. and Anaplasma marginale is based on the reading of Giemsa-stained blood or organ smears, which can have low sensitivity. Our aim was to improve the detection of bovine Babesia spp. and A. marginale by validating a multiplex PCR (mPCR). We used 466 samples of blood and/or organs of animals with signs and presumptive autopsy findings of babesiosis or anaplasmosis. The primers in our mPCR amplified the rap-1a gene region of Babesia bovis and B. bigemina, and the msp-5 region of A. marginale. We used a Bayesian model with a non-informative priori distribution for the prevalence estimate and informative priori distribution for estimation of sensitivity and specificity. The sensitivity and specificity for smear detection of Babesia spp. were 68.6% and 99.1%, and for A. marginale 85.6% and 98.8%, respectively. Sensitivity and specificity for mPCR detection for Babesia spp. were 94.2% and 97.1%, and for A. marginale 95.2% and 92.7%, respectively. Our mPCR had good accuracy in detecting Babesia spp. and A. marginale, and would be a reliable test for veterinarians to choose the correct treatment for each agent.