The body mass index is influenced by the environment in populations of Artibeus planirostris (Chiroptera: Phyllostomidae)?

Bats are the second most diverse taxa of mammals in the world, after rodents. Some studies have evaluated if there is a relationship between the environment and the morphology of bats, because environmental conditions can have an important influence on the phenotype of the species. The aim of the present study is to evaluate the relationship between a morphological variable (body mass index - BMI) of populations of the species Artibeus planirostris and the environment, considering the climatic variation in two hydrographic basins of the center of the Brazilian Amazon. The hypothesis is that the BMI responds to the environmental variables of each site. This will be higher during the rainy season and in the high water period, responding to a high availability of resources, according to studies carried out in the same region. 400 bats were captured, of which 180 were males and 220 were females. Although the index seemed to show differences considering the sex of the individuals, both in the Madeiras river basin (ANOVA: gl = 1, F = 6.90, P = .00) and in the Purus river (ANOVA: gl = 1, F = 3.95, P = .01), there was no significant difference between the BMI and the different environments, considering the climate season. It is concluded that, in this study, no evidence was found to support the hypothesis about the influence of the environment on BMI in populations of the bat species Artibeus planirostris in the center of the Brazilian Amazon.

Urbanisation Footprints and the Distribution of Air Quality in Nairobi City, Kenya

Various postulations on the relationship between urban morphology and air quality are qualitative. This fails to establish the strength of the contributions of each morphological parameter in the spatial distribution of the air quality. It is this gap in knowledge that this study sought to fill by modelling the correlation existing between the urban morphological variables of development density, land uses, biomass index and air quality values of Nairobi city. While 30 development zones of the city constituted the target population, IKONOS satellite imagery of the city for the year 2015 was utilised in establishing the development densities, land uses and biomass index. The parameters were transformed into numerical surrogates ranging from 1 to 10 with lower values accorded to zones with low biomass index, the highest development density, noxious land uses, high gaseous concentrations and vice-versa. Pearson’s correlation coefficients (r), coefficients of determination (R), t-tests and the Analysis of Variance (F-tests) with levels of significance being 95% were used to determine the strengths, significances and consistencies of the established relationships. The study established that development density is the most significant morphological variable influencing the distribution of air quality. This is followed by biomass index and to a weaker extent, land uses.

New -way(s) with -ward(s): lexicalization, splitting and sociolinguistic patterns

This paper investigates the distribution of a morphological variable that has not gained much attention in the literature: adverbial -s versus -Ø. This morpheme predominantly occurs with adverbs ending in -ward(s), like forward(s), afterward(s), and inward(s), or -way(s), such as anyway(s) or halfway(s). Using a large database of sociolinguistic interviews of Ontario English and an apparent-time perspective, we show that the use of the variants changes over the twentieth century, with the adverbial suffixes -ward(s) and -way(s) behaving differently. -Ward(s) shows a trend towards -s, while most words in -way(s) increasingly take -Ø–splitting by adverbial suffix. Anyway(s) is an exception to this pattern, with a change from below towards -s, strongly conditioned by social standing. We also find evidence for lexicalization of forms without -s in phrasal verbs like to move forward. We explain these findings against the background of variationist sociolinguistic theory and principles of language change.

Causality and History: Modes of Causal Investigation in Historical Social Sciences

Studies at the confluence of history and social science address issues of causation in three ways: morphological, variable-centered, and genetic. These approaches to causal investigation differ with regard to their modi operandi, the types of patterns they look for, their underlying assumptions and the challenges they face. Morphological inquiries elaborate causal arguments by uncovering patterns in the empirical layout of socio-historical phenomena. To this end, these inquiries draw on descriptive techniques of data formalization. Variable-centered studies engage causal issues by investigating patterns of association among empirical categories under the twofold assumption that these categories a priori have explanatory relevance and each category empirically has the same meaning across cases. Genetic analyses ground their causal claims by identifying patterned processes of emergence or production.

New combinations within the genus Sphagnum (Sphagnaceae, Bryophyta)

The genus Sphagnum is known for its morphological variable species, showing plastic responses along environmental gradients (Stenøien et al. 1997). Consequently, species delimitation based on morphological characters is not always straight forward. However, molecular analysis have in some cases pointed to differentiated entities within morphologically recognised taxa, e.g. Sphagnum fuscum (Schimper 1871:63) Klinggräff (1872:4) and Sphagnum magellanicum Bridel (1798:24) (Kyrkjeeide et al. 2015, Yousefi et al. 2017). In other cases, molecular markers have not resolved closely related taxa. A study based on isoenzymes could, for instance, not differentiate Sphagnum viride Flatberg (1988:9) from Sphagnum cuspidatum Ehrh. ex Hoffmann (1796:22) (Hanssen et al. 2000). Moreover, a study based on isoenzymes and RAPD could not differentiate Sphagnum isoviitae Flatberg (1992:2) and Sphagnum brevifolium (Lindb. ex Braithwaite (1878:84)) Röll (1889:340) from Sphagnum fallax (Klinggräff 1872:7) Klinggräff (1880: 128) (Såstad et al. 1999). Hence, the treatment of these taxa at the species level may be questioned. The material used in the studies was limited, and the use of more modern molecular markers might lead to other conclusions. Recognition of the taxa at variety level seems to be a reasonable solution, given our current knowledge. We therefore propose that S. viride, S. isoviitae and S. brevifolium be treated at the variety level while we await more comprehensive genetic studies, which may provide conclusive evidence concerning the status of these taxa.

Diameter of the base of the capitulum as a biometric variable of the goose barnacle Pollicipes pollicipes (Gmelin, 1789) (Cirripedia, Lepadomorpha)

Owing to the peculiar morphology of the goose barnacle Pollicipes pollicipes (Gmelin, 1789), many different biometric variables have been used in its study. The lack of a standard morphological variable makes it difficult to compare results from different authors. This aspect takes on even greater importance, since the goose barnacle is a commercially exploited species and must be regulated with clear-cut technical measures related to its biology. The need to measure a large quantity of specimens in the management and control of the fishery calls for a biometric variable that can be processed easily and requires little training. The base of the rostrum and the apex of the subcarina form two conspicuous clefts in the capitulum of the goose barnacle, allowing a calliper to be fitted quickly and easily. The results of this study showed that the diameter of the base of the capitulum (DBC), defined as the distance between these two clefts, may be considered a consistent variable both when the same specimen is measured by two different technicians and when the measurements taken from a fresh specimen are compared with the measurements taken after the specimen has been frozen and then thawed. In order to make comparisons easier, two linear equations have been found to relate DBC and two of the more usual biometric variables: rostral-carinal distance (RC) and capitulum height (CH). The mean length at sexual maturity was also calculated in terms of DBC (13.35 mm) for specimens collected on the Galician coast (NW Spain).

Some Secrets of Argania spinosa Water Economy in a Semiarid Climate

Argania spinosa is an example of an avoider tree growing under semi-arid conditions in Morocco. To assess what are the physiological strategies of this species, different variables were measured through an annual cycle in two populations located in the species’ main distribution area. Results show the expected decrease of leaf water potential (Ψ) with an increase of water-use efficiency (A/gs) with the onset of the dry season. In summer, leaf conductance (gs) was sensitive to vapour pressure deficit (VPD), and stomatal closure occurred over 30 mbar of VPD. Surprisingly, carbon isotope discrimination (δ13C) maintained very low values over the year, with almost no relationship with any physiological or morphological variable. Hence Argania spinosa presents a complex set of mechanisms to avoid water deficit, but δ13C cannot be used as an ecological tracer of long term WUE.

Limits to sustained energy intake

SUMMARY Links between resting metabolic rate (RMR) and reproductive output have been previously sought at both inter- and intraspecific levels, but have only been found in some interspecific studies. We aimed to examine correlations between RMR measured both prior to breeding and at peak lactation with litter size and litter mass in Mus musculus. By manipulating the litter size of some females at birth, we aimed to establish the direction of causality in any correlation between litter size and RMR. Correlations between maternal morphology and RMR, litter size and litter mass were also examined. Neither pre-breeding RMR nor mass-independent pre-breeding RMR was correlated with litter size or litter mass. RMR at peak lactation, however, was positively correlated with litter size and negatively correlated with mean pup mass. After correcting for the effects of body mass, residual peak lactation RMR was not correlated with litter size or litter mass. Body size was the major morphological variable influencing litter mass, offspring mass and asymptotic food intake. Mammary tissue mass was correlated with litter size when only the data for mice raising unmanipulated litters were used. RMR at peak lactation was significantly related to the principal component of morphology dominated by carcass mass. This study confirms the findings of previous intraspecific and some interspecific studies that found no correlation between RMR and reproductive output after the effects of body mass had been removed.

Predicting food consumption of fish populations as functions of mortality, food type, morphometrics, temperature and salinity

A large data set of relative food-consumption estimates (Q/B) of marine and freshwater fish populations (n = 108 populations, 38 species) is documented and used to derive a predictive model for Q/B, using asymptotic weight, habitat temperature, a morphological variable and food type as independent variables. Salinity is shown to have no effect on Q/B in fish well adapted to fresh or salt water (other things being equal), while mortality (Z), has a strong, positive effect on Q/B and on gross food-conversion efficiency (defined by GE = Z/(Q/B)), by affecting the ratio of small:large fish. The empirical models thus derived should be useful for parameterization of trophic models of ecosystems and similar applications.