Effect of duodenal infusion of trans10,cis12-CLA on milk performance and milk fatty acid profile in dairy goats fed high or low concentrate diet in combination with rolled canola seed

The effect of t10,c12-C18:2 on milk production, and fatty acid (FA) profile of milk fat was studied in 8 goats infused duodenally with t10,c12-C18:2 (2 g.10 h-1) during 3 days, followed by a 2-day infusion of skim milk (SM). The goats were assigned to 4 diets in a factorial arrangement constituted by low (L = 45%) or high (H = 65% of the diet DM) percentage of concentrate without (CS0) or with (CS20) rolled canola seed (20% of the concentrate DM). Milk samples were collected before (basal), and during the t10,c12-C18:2 and SM infusions. The t10,c12-C18:2 in milk fat increased from undetectable basal values to an average of 0.39% of total FA in the 3rd day of t10,c12-C18:2 infusion. DMI, milk yield, and the contents and yield of milk fat, protein, and lactose were similar between basal and the t10,c12-C18:2 infusion. The concentration of saturated FA with 4 to 16C did not change during the t10,c12-C18:2 infusion, whereas C18:0 increased, particularly in the milk fat of the CS20 group. The t10,c12-C18:2 infusion increased the t10- and t11-C18:1 (except a reduction in t11-C18:1 for the H-CS20 group), and it decreased the c9,t11-C18:2 in milk fat, particularly for the H-CS20 group. The t10,c12-C18:2 infusion reduced the c9,t11-C18:2/t11-C18:1 ratio, particularly for the CS0 group. The results indicate that mammary lipogenesis in dairy goats was not decreased by t10,c12-C18:2, however, the desaturation of long chain FA appeared to be equally affected as in dairy cows. This reduction in the desaturase index of milk fat could have been a direct effect of t10,c12-C18:2, or mediated via an increase in t10-C18:1.     

Spatial Bias in the Marine Fossil Record

Inference of past and present global biodiversity requires enough global data to distinguish biological pattern from sampling artifact. Pertinently, many studies have exposed correlated relationships between richness and sampling in the fossil record, and methods to circumvent these biases have been proposed. Yet, these studies often ignore paleobiogeography, which is undeniably a critical component of ancient global diversity. Alarmingly, our global analysis of 481,613 marine fossils spread throughout the Phanerozoic reveals that where localities are and how intensively they have been sampled almost completely determines empirical spatial patterns of richness, suggesting no separation of biological pattern from sampling pattern. To overcome this, we analyze diversity using occurrence records drawn from two discrete paleolatitudinal bands which cover the bulk of the fossil data. After correcting the data for sampling bias, we find that these two bands have similar patterns of richness despite markedly different spatial coverage. Our findings suggest that i) long-term diversity trends result from large-scale tectonic evolution of the planet, ii) short-term diversity trends are region-specific, and iii) paleodiversity studies must constrain their analyses to well-sampled regions to uncover patterns not driven by sampling.     

Low lipoprotein(a) concentration is associated with cancer and all-cause deaths: a population-based cohort study (the JMS cohort study)

Background

Experimental studies support the anti-neoplastic effect of apo(a), but several clinical studies have reported contradictory results. The purpose of this study was to determine whether a low lipoprotein(a) [Lp(a)] concentration is related to mortality from major causes of death, especially cancer.

Methods

The subjects were 10,413 participants (4,005 men and 6,408 women) from a multi-center population-based cohort study in Japan (The Jichi Medical School cohort study). The average age at registration was 55.0 years, and the median observation period was 4,559 days. As the estimated hazard ratio was high for both the low and very high Lp(a) levels, we defined two Lp(a) groups: a low Lp(a) group [Lp(a)<80 mg/L] and an intermediate-to-high Lp(a) group [Lp(a)≥80]. Participants who died from malignant neoplasms (n = 316), cardiovascular disease (202), or other causes (312) during the observation period were examined.

Results

Cumulative incidence plots showed higher cumulative death rates for the low Lp(a) group than for the intermediate-to-high Lp(a) group for all-cause, cancer, and miscellaneous-cause deaths (p<0.001, p = 0.03, and p = 0.03, respectively). Cox proportional hazards analyses with the sex and age of the participants, body mass index, and smoking and drinking histories as covariates showed that a low Lp(a) level was a significant risk for all-cause, cancer, and miscellaneous-cause deaths (p<0.001, p = 0.003, and p = 0.01, respectively). The hazard ratio (95% CI) [1.48, 1.15–1.92] of a low Lp(a) level for cancer deaths was almost the same as that for a male sex (1.46, 1.00–2.13).

Conclusions

This is the first report to describe the association between a low Lp(a) level and all-cause or cancer death, supporting the anti-neoplastic effect of Lp(a). Further epidemiological studies are needed to confirm the present results.     

Monitoring indole alkaloid production by Penicillium digitatum during infection process in citrus by Mass Spectrometry Imaging and molecular networking

Green mold, caused by Penicillium digitatum, is the most destructive post-harvest disease in citrus. Secondary metabolites produced by fungal phytopathogens have been associated with toxicity to their respective host through the interaction with a wide range of cell targets. Natural products have also been described as important molecules for biocontrol and competition in their respective environment. For P. digitatum, the production of indole alkaloids, tryptoquialanines A and B, have been reported. However, their biological role remains unknown. Mass Spectrometry Imaging (MSI) technique was applied here for the first time to monitor the secondary metabolites produced on the orange surface during infection in order to gain insights about the P. digitatum-citrus interaction mechanisms. Through the combination of MSI and molecular networking it was possible to report, for the first time, the production of tryptoquivalines and fumiquinazolines by P. digitatum and also the accumulation of tryptoquialanines on the fruit surface from 4 to 7 d post inoculation. P. digitatum was also evaluated concerning the ability to sinthesize indole alkaloids in vivo in the different citrus hosts. The biological role of tryptoquialanines was investigated and tryptoquialanine A was submitted to insecticidal bioassays that revealed its high toxicity against Aedes Aegypti, suggesting an important insecticidal action during orange decay.     

Nodal dynamics, not degree distributions, determine the structural controllability of complex networks

Structural controllability has been proposed as an analytical framework for making predictions regarding the control of complex networks across myriad disciplines in the physical and life sciences (Liu et al., Nature:473(7346):167-173, 2011). Although the integration of control theory and network analysis is important, we argue that the application of the structural controllability framework to most if not all real-world networks leads to the conclusion that a single control input, applied to the power dominating set, is all that is needed for structural controllability. This result is consistent with the well-known fact that controllability and its dual observability are generic properties of systems. We argue that more important than issues of structural controllability are the questions of whether a system is almost uncontrollable, whether it is almost unobservable, and whether it possesses almost pole-zero cancellations.     

Long-term effects of forest fragmentation on Amazonian ant communities

Aim To analyse the effects of forest fragmentation on ant communities in an Amazonian landscape that has been fragmented for over a century. Location The region surrounding the village of Alter do Chão in the Brazilian Amazonian state of Pará (2°30′ S, 54°57′ W). Methods Collection of ants and measurements of tree density were performed along transects established in eight sites in continuous forest and in 24 forest fragments surrounded by savanna vegetation. Data on size, perimeter, and degree of isolation (distance to continuous forest and distance to nearest area of forest > 5 ha) of each fragment were obtained from a georeferenced Landsat image of the study area. Results There were significant differences in species richness and composition between fragments and continuous forest, and these differences were not related to intersite variation in vegetation structure (tree density). Fragments supported fewer ant species per plot, and these species tended to represent a nested subset of those found in continuous forests. Fragments had significantly fewer rare species and fewer ant genera. However, fragments and continuous forest had similar numbers of species that also occur in the savanna matrix (i.e. that are not forest specialists). Multiple linear regression analyses indicated that species richness and composition in the fragments are significantly affected by fragment area, but not by fragment shape and degree of isolation. More species were found in larger fragments. Main conclusions Forest fragmentation influences the organization of ant communities in Amazonian savanna/forest landscapes. Forest fragments harboured, on average, 85% of the species found in continuous forest. That these fragments, despite their long history of isolation, support a relatively large complement of the species found in continuous forest is surprising, especially given that in some recently fragmented landscapes the proportion of species surviving in the fragments is lower. Differences in inter‐fragment distance and type of matrix between Alter do Chão and these other landscapes may be involved. The fact that fragments at Alter do Chão are surrounded by a natural (rather than an anthropogenic) habitat, and that most of them are less than 300 m from another forest area, may have helped to ameliorate the adverse effects of forest fragmentation.     

A novel apical midpiece defect in the spermatozoa of a bull without an apparent decrease in motility and fertility. A case study

Despite some limitations as predictors of fertility, evaluation of sperm morphology and progressive motility is the commonest method to assess viability of frozen/thawed semen. In this article we describe by light and transmission electron microscopy a novel midpiece structural defect observed in 24-36% of frozen/thawed sperm cells from a Charolais bull, used in artificial insemination programs without any apparent ill effect to the fertility. After thawing, the sperm progressive motility ranged from 65 to 80% and the pregnancy rate for all artificial inseminations performed (43%) did not differ (p>0.05) from results obtained with insemination with semen of other bulls (40%). The defect consisted in mitochondrial aplasia at the neck region, mitochondrial segmental elongation and gaps and thickening of the outer dense fibers at the apical region of the midpiece, and loss of the cementing substance and development of plasma membrane extensions in the entire midpiece. No structural abnormalities were found in the capitulum, proximal centriole, striated columns, axoneme, annulus and fibrous sheath. The thickness of the outer fibers returned to normal at the distal region of the midpiece. Based on the examination it is suggested that the alterations might be originally caused by loss of the cementing substance that links mitochondria to the plasma membrane in association with mitochondrial aplasia at the neck region of the midpiece. The abnormality appeared not related to other described sperm defect syndromes, although it shared particular characteristics with the dag defect, segmental aplasia of the mitochondrial sheath, corkscrew defect and pseudodroplet defect.     

Patterns of ant species diversity and turnover across 2000 km of Amazonian floodplain forest

Aim To determine the effect and relative importance of geographic and local environmental factors on species richness and turnover of ant assemblages in floodplain forests across the Amazon basin. Location Twenty‐six mature forest sites scattered along the entire extension of the Amazon River in Brazil. The study area encompassed nearly 18° of longitude and 3.5° of latitude. Methods Systematic collections of ants were performed at each site during the low‐water season (i.e. when forests are not inundated) using three complementary sampling methods. We used variance partitioning techniques to assess the relative effects of the spatial (latitude and longitude) and environmental (rainfall, length of the dry season and flood height) variables on ant species richness and composition. Results There was a twofold variation in the number of species per site, which was largely explained by inter‐site variations in rainfall seasonality and flooding intensity. In general, there were more species at sites located in the western part of the basin, where the dry season is less severe, or near the river estuary, where precipitation is also high and flooding is less intense. Ant community composition was also affected by environmental heterogeneity. For instance, some species only occurred at those sites less affected by the river’s seasonal flooding, whereas others were mostly associated with the drier or wetter regions of the basin. In addition, the turnover of species increased significantly as geographic distances increased. Nevertheless, the rate of change was small given that many species had a broad distribution across the study area. Main conclusions Ant distribution patterns along the floodplain forests of the Amazon appear to be controlled to a relatively large extent by the current gradient in flooding intensity and – most importantly – in precipitation. Altered rainfall regimes resulting from global warming and land‐use change thus have the potential to influence these patterns.     

Involvement of K+ channels and calcium-dependent pathways in the action of T3 on amino acid accumulation and membrane potential in Sertoli cells of immature rat testis

The purpose of this study was to investigate the involvement of calcium in K+ currents and its effects on amino acid accumulation and on the membrane potential regulated by tri-iodo-L-thyronine (T3) in Sertoli cells. Immature rat testes were pre-incubated for 30 min in Krebs-Ringer bicarbonate buffer and incubated for 60 min in the presence of [14C]methylaminoisobutyric acid with and without T3 or T4 (dose-response curve). Specific channel blockers or chelating agents were added at different concentrations during pre-incubation and incubation periods to study the basal amino acid accumulation and a selected concentration of each drug was chosen to analyze the influence on the stimulatory hormone action. All amino acid accumulation experiments were carried out in a Dubnoff metabolic incubator at 32 degrees C, pH 7.4 and gassed with O2:CO2 (95:5; v/v). Seminiferous tubules from immature Sertoli cell-enriched testes were used for the electrophysiology experiments. Intracellular recording of the Sertoli cells was carried out in a chamber perfused with KRb with/without T3, T4 or blockers and the membrane potential was monitored. We found that T3 and T4 stimulated alpha-[1-14C] methylaminoisobutyric acid accumulation in immature rat testes and induced a membrane hyperpolarization in Sertoli cells. The action of T3 on amino acid accumulation and on the hyperpolarizing effect was inhibited by the K(+)-ATP channel blocker tolbutamide as well as the voltage-dependent Ca2+ channel blocker verapamil. These results clearly demonstrate for the first time the existence of an ionic mechanism related to Ca2+ and K+ fluxes in the rapid, nongenomic action of T3.