The integrity of chromatin in the spermatozoon is essential for reproductive outcome. The aim of this study was to evaluate the most effective and cost-effective method to reduce the percentage of spermatozoa with defects in chromatin decondensation for use in assisted reproductive technologies (ART) procedures. Sperm samples from 15 sub-fertile males were examined at CFA Naples to determine the sperm decondensation index (SDI), using the aniline blue test, before and after preparation, comparing density gradients with two different swim-up approaches. All three techniques led to a reduction in decondensed spermatozoa with no statistical difference (P > 0.05) between the control and the treated sperm. In contrast, we found a highly significant decrease in SDI (P < 0.01) after the two swim-up methods in all the samples, confirming the efficacy of these methods in lowering the percentage of chromatin compaction damage. There was no statistical difference between the two swim-up methods, however swim-up from the pellet led to improved count, motility and the percentage of normal condensed spermatozoa. We suggest that swim-up from the pellet be used in ART on sub-fertile males, both to reduce cell stress by multiple centrifugation and improve the recovery rate of mature spermatozoa.

Afar in Ethiopia is a drought prone area characterized by low rainfall, high temperature and suffering from flash flood emerging from adjacent mountains. We introduced a flood barrier, water spreading weirs (WSWs) in 2015 to convert floods to a productive use and assessed its effect in 2016 and 2017. WSWs resulted in deposition of sediments where sand deposition was higher in the upside of upstream weir whereas silt and clay deposition was prominent at the central location between the two weirs. There was a moisture gradient across farming fields with volumetric water content (VWC) at 20 cm depth varying between 10 and 22% depending on the relative position/distance of fields from the WSWs, consequently, effecting significant difference in yield between fields. There was a positive relationship between VWC made available by WSWs at planting and the yield (P < 0.001, r = 0.76) and biomass productivity (P < 0.005, r = 0.46). WSWs created differing farming zone following soil moisture regime, affecting grain and biomass yield. In good potential zones with high moisture content, the WSW-based farming enabled to produce up to 5 and 15 t ha−1 yr−1 of maize grain and biomass, respectively, while in low potential zones there was a complete crop grain failure. The system enabled pastoralists to produce huge amount of biomass and grain during Belg (short) and Meher (long) growing seasons that was stored and utilized during succeeding dry periods. Furthermore, the practice ensured a visible recovery of degraded rangelands. This was evident from the filling up of the riverbed as well as the two WSW wings with 1 m high and about 450 m length each with fertile sediment from Belg and Meher seasons of 2016 and 2017. Hence, future studies should analyze the sustainability and the potential of flood-based development at large scale.

We are performing systematic observation studies on the Galactic interstellar isotopic ratios, including 18O/17O, 12C/13C, 14N/15N and 32S/34S. Our strategy focuses on combination of multi-transition observation data toward large samples with different Galactocentric distances. Our preliminary results show positive Galactic radial gradients of 18O/17O and 12C/13C. In both cases, the ratio increases with the Galactocentric distance, which agrees with the inside-out scenario of our Galaxy. Observations of other isotopes such as 14N/15N and 32S/34S are on-going.

In this paper we obtain the local Hölder regularity of the gradients of weak solutions for a class of non-uniformly nonlinear variable exponent elliptic equations in divergence form

including the following special model

under some proper assumptions on Ai and the Hölder continuous functions f, pi(x) for i = 1, 2.

How does sign language compare with gesture, on the one hand, and spoken language on the other? Sign was once viewed as nothing more than a system of pictorial gestures without linguistic structure. More recently, researchers have argued that sign is no different from spoken language, with all of the same linguistic structures. The pendulum is currently swinging back toward the view that sign is gestural, or at least has gestural components. The goal of this review is to elucidate the relationships among sign language, gesture, and spoken language. We do so by taking a close look not only at how sign has been studied over the past 50 years, but also at how the spontaneous gestures that accompany speech have been studied. We conclude that signers gesture just as speakers do. Both produce imagistic gestures along with more categorical signs or words. Because at present it is difficult to tell where sign stops and gesture begins, we suggest that sign should not be compared with speech alone but should be compared with speech-plus-gesture. Although it might be easier (and, in some cases, preferable) to blur the distinction between sign and gesture, we argue that distinguishing between sign (or speech) and gesture is essential to predict certain types of learning and allows us to understand the conditions under which gesture takes on properties of sign, and speech takes on properties of gesture. We end by calling for new technology that may help us better calibrate the borders between sign and gesture.

This study examined patterns in the species richness and abundance of small non-volant mammals along a tropical altitudinal gradient in north-eastern Australia. We investigated whether a mid-altitudinal peak in diversity was apparent, and if it occurred, whether it was determined by particular environmental conditions. We sampled a small-mammal assemblage at 17 sites distributed along an altitude-environmental gradient from savanna (350 m) to rain-forest vegetation (1000 m). Over four separate occasions (5100 trap-nights) we recorded 17 species of mammal with 416 captures. A positive non-linear relationship between altitude and mammal species richness and abundance was observed, peaking at the 800–900 m range. Many species were distributed across a range of altitudes, while others were strongly associated with particular habitat conditions. There was a distinct reduction in abundance and species richness at low altitudes associated with the less complex vegetation, lower productivity and possible anthropogenic effects. Key findings were: that small-mammal richness peaked towards the summit of the gradient and not at one-half the maximum altitude predicted by the mid-domain effect; contrasting conditions and greatest vegetation juxtaposition had the greatest influence on the patterns recorded; and that local idiosyncratic influences such as habitat factors, land management and historical biogeography are significant.

Introduction. Mature green vanilla pods accumulate 4-O-(3-methoxy-benzaldehyde)-β-D-glucoside (glucovanillin), which, upon hydrolysis by an endogenous b-glucosidase, liberates vanillin, the major aroma component of vanilla. Little is known on the spatial distribution of aroma-generating phenolics, and the enzymes responsible for their liberation (β-glucosidase) and oxidation (peroxidase). We report here quantitative data with respect to these three components in relation to the anatomy of the pod. Furthermore, the spatial progression of oxidation is shown. Materials and methods. Mature green vanilla pods were analyzed for their contents of phenolics (HPLC), and β-glucosidase and peroxidase activities by spectrophotometric techniques using p-nitrophenyl glucoside and vanillin as substrates, respectively. Lipids were examined under fluorescence microscopy after Nile red staining. Oxidation development was observed on transverse slices of pods. Results and discussion. Phenolics, and β-glucosidase and peroxidase activities showed gradients of increasing-decreasing concentrations from the stem to the blossom end of pods. The β-glucosidase activity is distributed in between the placentae, mesocarp, and trichomes in a [7 / 2 / 1] proportion while that of peroxidase shows a [38 / 1] ratio in the mesocarp and placentae, and was absent from trichomes. Oxidation begins from the blossom end in the placentae, progressively invading the mesocarp and moving towards the stem end. Conclusion. The green mature vanilla pod is spatially heterogeneous for its phenolics, and β-glucosidase and peroxidase activities, its placentae playing an important role in the liberation of vanillin and its subsequent oxidation.

Soil water potentials were measured weekly by psychrometers at 20 cm depth during the dry season in a tropical moist forest on Barro Colorado Island, Panama. There was a persistent gradient of decreasing soil moisture from gap centre to gap edge to adjacent understorey at both a large and a small gap. On both a north-south and an east-west transect, the soil was drier (water potentials were more negative) on an upland surface than on moderate slopes. This trend was reflected in the predawn, total water potentials of shallow-rooted Psychotria horizontalis and deep-rooted Trichilia tuberculata measured in the understorey during the last two months of the dry season. P. horizontalis from the wettest sites on the transects had higher osmotic potentials at full hydration and at zero turgor, indicating less drought resistance than for conspecifics from the driest sites.

A survey of the diurnal raptor community (46 resident species) at five altitudinal levels from 100 to 4600 m was made in Venezuela using 106 1-km2 sample quadrats and then compared with similar censuses (211 plots) in southwestern Colombia and eastern Ecuador. Six habitat types were defined and habitat preferences were measured from every encountered birds and from the association between individual abundances and the coverage of habitat types on plots. The overall species richness steeply declined with elevation in all three countries. The raptor community consisted mostly of tropical species that rapidly decreased in both abundance and frequency of occurrence with elevation. A small set of subtropical-temperate forest specialists partly replaced them at mid-elevation and only two species occurred in the paramo of Venezuela, against 5–7 in the other countries. Although originally the gradients were probably almost completely covered with forest, a large part of the raptor community is now composed of grassland species, three of them extending from the lowlands to the tree line. The relative impoverishment of the Venezuelan community, especially at upper levels, is attributed to a peninsular effect at the narrow extreme northern tip of the Andes and perhaps also to former forest fragmentation. Within some species, different subspecies had discrete altitudinal distributions and interspecific competition may explain differences in the range extension of some species between countries. Today, however, accelerating deforestation may result in a severe decline of forest-interior species and a probable reduction in the altitudinal range of at least some of them. Species naturally associated with forest gaps or edges usually tolerate a high degree of forest fragmentation and degradation but only one of them may become abundant in heavily human-altered woodlands. Few grassland specialists have become more widely distributed in the increasingly deforested landscapes.

The peripheral retina of the sea lamprey develops in a 5-year-long process in which only certain neurons differentiate each year. The growth of cell layers, the differentiation of the neurons, and the morphology of their dendrites and axons were studied with normal, HRP, and Golgi preparations. Ganglion cells are differentiated in 3-year-old larvae, amacrine and horizontal cells in 4-year-old larvae, photoreceptor cells in stage I transformers, and bipolar cells in stage III transformers. Each new development is expressed as a radial gradient of differentiation. As a result of this protracted and stepped process, lamprey retinal neurons, particularly ganglion cells, differentiate in the absence of other cells to which they will ultimately be connected and may express their individual genetic programs more fully than in other vertebrate retinas. This could account for the unusual relationship of the ganglion cell, inner plexiform, and optic nerve layers and for the very high ratio of displaced to orthotopic ganglion cells.

The dynamics modeling and payload adaptability of a light-weight flexible one-link manipulator are studied. Using the FEM (Finite-Element Method) model of a flexible manipulator, a lower order Linear Quadratic Gaussian compensator can provide satisfactory performance without controller/observer spillover. Moreover, the payload can be separated from the beam model, therefore, it is expected that the identification algorithm should have better robustness than the other schemes. The simulation results have shown that the proposed payload-adaptation synthesizer, which synthesizes a payload identifier and a nominal regulator/estimator interpolator to obtain a near-optimal compensator, has good adaptability with varying payload. And the resulting synthesizer also provides a near-optimal damping for this sensor-actuator noncolocated system.

Using monoclonal anti-calmodulin antibodies in conjunction with confocal scanning laser microscopy we have analysed the spatial variations in the distribution pattern of calmodulin (CaM) during the sequential events of pollen hydration, germination and tube growth in Nicotiana tabacum. These immunocytochemical observations have been complemented by immunochemical studies wherein the anti-calmodulin antibody raised against pea CaM recognises a polypeptide of c. 18 kDa in the pollen extracts. Digitisation of confocally acquired optical sections of immunofluorescence images reveals that in hydrated pollen a high level of CaM is consistently present in the region of the germinal apertures. Subsequently, with the onset of germination a high CaM concentration was found associated with the plasma membrane of the germination bubble and in the cytoplasm in its vicinity, while in the vegetative cytoplasm a weak diffuse and intense punctate signal was registered. CaM immunostain was also detected in association with the plasma membrane of the tube tips in both short and long pollen tubes. Furthermore, the cytosol of the tubes invariably manifested an apically focused CaM gradient. We were, however, unable to detect any vacuolar association of CaM in the older regions of the pollen tubes. Although punctate immunostain was obvious across the pollen tube numerous punctate structures were invariably present in the extreme tip. The possible implications of these findings in development of cell polarity, polarised growth, maintenance of calcium homeostasis and CaM interactions with other mechanochemical motor proteins in effecting propulsion of organelles during pollen hydration, germination and pollen tube growth are discussed.

Resource partitioning has been hypothesized to play a role in the maintenance of tree diversity in tropical forests. We looked for evidence of light and soil moisture partitioning among seedlings of four native Malagasy tree species, the pioneer, gap-adapted species Harungana madagascariensis and the three shade-tolerant species Ocotea cymosa, Stephanostegia capuronii and Uapaca ferruginea. Four hundred and eighty seedlings were transplanted in experimental plots in the Tampolo coastal forest and grown for 2 y. Growth rates increased with increasing light availability for all species, and with increasing dry-season soil moisture for H. madagascariensis. With increasing light availability, survival increased for H. madagascariensis, S. capuronii and U. ferruginea but decreased for O. cymosa. While dry-season soil moisture did not influence the growth or survival of the shade-tolerant species, it interacted with understorey light in its effect on the performance of H. madagascariensis, which performed better in wet soils at high light than in dry soils in shade. Rank reversals in species performance suggested that three of the four tree species partition resource gradients as seedlings, mostly light and secondarily dry-season soil moisture. There was only partial agreement between the performance of transplanted seedlings and the distribution of natural seedlings of the same four species with respect to light and soil moisture, suggesting that the success of tropical tree regeneration can only be partly accounted for by seedling performance across resource gradients.

Geometrid moths were collected on Mt. Kinabalu (Sabah, Malaysia) along two habitat gradients, ranging from primary rain forest to cultivated areas. During 135 nights' trapping in 1997, 4585 individuals representing 500 species were attracted by light. Primary forest samples and those from old-grown regenerated forest exhibited high diversity (Fisher's α = 75–128), while agricultural areas as well as most secondary forests had a significantly lower diversity (α = 34–61). One 15-y-old secondary forest with a rich undergrowth vegetation also housed a diverse geometrid community (α = 89). In three paired samples, diversity of geometrid moths in the canopy was equal to or lower than in the understorey. Of six habitat variables tested, only undergrowth plant species diversity emerged as a significant predictor of geometrid diversity. The NESS index, in combination with multi-dimensional scaling, was used to investigate patterns of between-habitat diversity. Of two dimensions extracted, one represented the degree of habitat disturbance, while the other separated the two study areas. Geometrid samples of strongly disturbed habitats did not converge between sites, indicating that apart from the degree of human interference the regional species pool was also important in determining similarity among local communities.