Effects of climate on soil phosphorus cycle and availability in natural terrestrial ecosystems

Climate is predicted to change over the 21st century. However, little is known about how climate change can affect soil phosphorus (P) cycle and availability in global terrestrial ecosystems, where P is a key limiting nutrient. With a global database of Hedley P fractions and key-associated physiochemical properties of 760 (seminatural) natural soils compiled from 96 published studies, this study evaluated how climate pattern affected soil P cycle and availability in global terrestrial ecosystems. Overall, soil available P, indexed by Hedley labile inorganic P fraction, significantly decreased with increasing mean annual temperature (MAT) and precipitation (MAP). Hypothesis-oriented path model analysis suggests that MAT negatively affected soil available P mainly by decreasing soil organic P and primary mineral P and increasing soil sand content. MAP negatively affected soil available P both directly and indirectly through decreasing soil primary mineral P; however, these negative effects were offset by the positive effects of MAP on soil organic P and fine soil particles, resulting in a relatively minor total MAP effect on soil available P. As aridity degree was mainly determined by MAP, aridity also had a relatively minor total effect on soil available P. These global patterns generally hold true irrespective of soil depth (≤10 cm or >10 cm) or site aridity index (≤1.0 or >1.0), and were also true for the low-sand (≤50%) soils. In contrast, available P of the high-sand (>50%) soils was positively affected by MAT and aridity and negatively affected by MAP. Our results suggest that temperature and precipitation have contrasting effects on soil P availability and can interact with soil particle size to control soil P availability.

A global synthesis of the rate and temperature sensitivity of soil nitrogen mineralization: latitudinal patterns and mechanisms

Soil net nitrogen (N) mineralization (N_min ) is a pivotal process in the global N cycle regulating the N availability of plant growth. Understanding the spatial patterns of N_min, its temperature sensitivity (Q₁₀ ) and regulatory mechanisms is critical for improving the management of soil nutrients. In this study, we evaluated 379 peer-reviewed scientific papers to explore how N_min and the Q₁₀ of N_min varied among different ecosystems and regions at the global scale. The results showed that N_min varied significantly among different ecosystems with a global average of 2.41 mg N soil kg^-1  day^-1 . Furthermore, N_min significantly decreased with increasing latitude and altitude. The Q₁₀ varied significantly among different ecosystems with a global average of 2.21, ranging from the highest found in forest soils (2.43) and the lowest found for grassland soils (1.67) and significantly increased with increasing latitude. Path analyses indicated that N_min was primarily affected by the content of soil organic carbon (C), soil C:N ratio, and clay content, where Q₁₀ was primarily influenced by the soil C:N ratio and soil pH. Furthermore, the activation energy (E_a ) of soil N mineralization was significantly and negative correlated with the substrate quality index among all ecosystems, indicating the applicability of the carbon quality temperature hypothesis to soil N mineralization at a global scale. These findings provided empirical evidence supporting that soil N availability, under global warming scenarios, is expected to increase stronger in colder regions as compared with that low-latitude regions due to the higher Q₁₀ . This may alleviate the restriction of N supply for increased primary productivity at higher latitudes.

Vojta method in the treatment of developmental hip dysplasia - a case report

Background

Developmental dysplasia of the hip joint is one of the most common congenital defects and often results in functional and structural disorders. Such cases particularly demand optimizing therapeutic effects and maximally reducing the duration of therapy.

Purpose

The aim of this case report is to present the therapeutic process in a child with developmental hip dysplasia.

Case report

This is a case report of a female child with a birth weight of 2,800 g and an Apgar score of 9 points born to a gravida 3 para 3 mother at 37 weeks. The child was delivered by cesarean section, and the pregnancy was complicated by oligohydramnios. Subluxation of the left hip joint was diagnosed by an orthopedist in the third month of life. The treatment followed was the Vojta method (the first phase of reflex turning and reflex crawling).

Results

During the 6 weeks of the Vojta treatment, the left half of the femoral head was centralized, and the process of formation of the hip joint acetabulum was influenced effectively enough to change the acetabulum’s Graff type from the baseline D to IIb after 41 days of treatment.

Conclusion

The diagnostic work-up of congenital hip joint dysplasia should involve a physiotherapist who will investigate the child’s neuromuscular coordination, in addition to a neonatologist and a pediatrician. The therapy for a disorder of hip joint development of neuromotor origin should involve the application of global patterns according to Vojta. Children with congenital dysplasia of the hip joint should commence rehabilitation as early as possible.

Whole-genome sequencing of two North American Drosophila melanogaster populations reveals genetic differentiation and positive selection

The prevailing demographic model for Drosophila melanogaster suggests that the colonization of North America occurred very recently from a subset of European flies that rapidly expanded across the continent. This model implies a sudden population growth and range expansion consistent with very low or no population subdivision. As flies adapt to new environments, local adaptation events may be expected. To describe demographic and selective events during North American colonization, we have generated a data set of 35 individual whole-genome sequences from inbred lines of D. melanogaster from a west coast US population (Winters, California, USA) and compared them with a public genome data set from Raleigh (Raleigh, North Carolina, USA). We analysed nuclear and mitochondrial genomes and described levels of variation and divergence within and between these two North American D. melanogaster populations. Both populations exhibit negative values of Tajima's D across the genome, a common signature of demographic expansion. We also detected a low but significant level of genome-wide differentiation between the two populations, as well as multiple allele surfing events, which can be the result of gene drift in local subpopulations on the edge of an expansion wave. In contrast to this genome-wide pattern, we uncovered a 50-kilobase segment in chromosome arm 3L that showed all the hallmarks of a soft selective sweep in both populations. A comparison of allele frequencies within this divergent region among six populations from three continents allowed us to cluster these populations in two differentiated groups, providing evidence for the action of natural selection on a global scale.