Decreasing pH impairs sexual reproduction in a Mediterranean coral transplanted at a CO2 vent

Ocean acidification, due to the increase of carbon dioxide (CO₂) concentration in the atmosphere and its absorption by the oceans, affects many aspects of marine calcifying organisms' biology, including reproduction. Most of the available studies on low pH effects on coral reproduction have been conducted on tropical species under controlled conditions, while little information is reported for either tropical or temperate species in the field. This study describes the influence of decreasing pH on sexual reproduction of the temperate non-zooxanthellate colonial scleractinian Astroides calycularis, transplanted in four sites along a natural pH gradient at the underwater volcanic crater of Panarea Island (Tyrrhenian Sea, Italy). The average pH values of each site (range: pH_TS 8.07-7.40) match different scenarios of the Intergovernmental Panel on Climate Change (IPCC) for the end of the century. After 3 months under experimental conditions, the reproductive parameters of both oocytes and spermaries (abundance, gonadal index, and diameters) seem to be unaffected by low pH. However, a delay in spermary development in the pre-fertilization period and a persistence of mature oocytes in the fertilization period were observed in the most acidic site. Furthermore, no embryos were found in colonies from the two most acidic sites, suggesting a delay or an interruption of the fertilization process due to acidified conditions. These findings suggest a negative effect of low pH on A. calycularis sexual reproduction. However, long-term experiments, including the synergistic impact of pH and temperature, are needed to predict if this species will be able to adapt to climate change over the next century.

Amphipithecine primates are stem anthropoids: cranial and postcranial evidence

Since their discovery in 1927, the phylogenetic status of the Myanmar amphipithecines has been highly debated. These fossil primates are recognized either as anthropoids or as adapiform strepsirrhines. This uncertainty was largely the consequence of a limited fossil record consisting mostly of jaw fragments but lacking the critical cranial elements that might resolve this debate. We report here cranial remains associated with an ulna from a single individual pertaining to the amphipithecine Ganlea megacanina. In addition to anthropoid-like dentognathic characters, Ganlea displays several ulna and skull features that testify to its anthropoid affinities (e.g. short subvertically oriented lacrimal duct, lacrimal foramen and bone inside the orbit, maxillary contribution to the lower orbital rim, fused metopic suture). By contrast to crown anthropoids, however, Ganlea lacks postorbital closure, confirming that postorbital closure appeared later than many anthropoid dentognathic characters and evolved convergently in extant tarsiers and anthropoids. Thus, amphipithecines must now be recognized as stem anthropoids offering a unique window on the early evolution of cranial and skeletal features in anthropoids, and reinforcing the hypothesis of an origin and early diversification of anthropoids in Asia.

Prevalence of low back pain and its effect on health-related quality of life in 409 scholar adolescents from the Veneto region

Low back pain (LBP) is a common condition with profound effects on well-being. We aimed to define the prevalence and the characteristics of LBP and to investigate its impact on the quality of life (QoL) of 409 students (265 females and 144 males), all high-school adolescents from the Veneto region. LBP was measured with a structured, self-report questionnaire, while the SF-36 questionnaire was used to measure physical and mental QoL. 253 students (61.3%) reported one or more episodes of LBP, with female predominance. Adolescents with LBP treated with drugs and rehabilitation cares have significantly poor belief in pain resolution (p=0.005), but more belief in a prevention program (p=0.006) than the others. After adjustment for sex, a significant association between the SF-36 dimension of vitality and the presence of LBP in males was observed. All SF-36 domains except mental health were significantly higher in females with LBP. Our study confirmed that LBP is frequent in Italian scholar adolescents and has an impact on QoL. Strategies for reducing the effects of LBP on QoL should be an important purpose for clinicians and health policy makers.

Enamel Distribution in 3D: Is Enamel Thickness More Uneven in the Upper Second Molars of Durophagous Hominoids?

Enamel thickness is not uniform across the dental crown of primates. It has been suggested that enamel distribution could be used in taxonomy or for ecological inferences. For instance, the thickness of molar enamel in mammals consuming hard food is expected to be uneven, despite differing reports on extant and extinct apes. Overall estimations of average and relative enamel thickness may mask the details of enamel distribution in complex teeth such as molars. Investigating enamel distribution and its purported relationship with ecology or phylogeny would require more detailed assessments. This paper aims to assess whether apes that consume hard foods on a regular basis, such as Pongo pygmaeus, can be characterized by the evenness or unevenness of enamel thickness. To do so, we combined topographic maps and distribution histograms of enamel thickness with cumulative profiles of its variation, or “pachymetric profiles”. We investigated a sample of 25 unworn hominoid upper second molars scanned by X-ray microtomography, and further compared this to a sample of 32 cercopithecines and colobines. Topographic maps show uniformly thin enamel for Gorilla gorilla and Hylobates sp., unevenly thin enamel for Pan paniscus and Pan troglodytes, and unevenly thick enamel for Pongo pygmaeus. The skewness of enamel distribution does not distinguish between ape species, but does separate apes from OldWorld monkeys. Contrary to previous reports on OldWorld monkeys, the slope of enamel thickness profiles, or pachymetric slope, does not predict the diet of extant apes. However, it does separate the Pan genus, which is characterized by a higher pachymetric slope indicating more uneven enamel distribution compared to other apes. The uneven thickness of enamel distribution observed on topographic maps for P. pygmaeus is not supported by its low pachymetric slope, which instead indicates uniform enamel distribution. This discrepancy in the results obtained for P. pygmaeus can be interpreted as an evolutionary tradeoff between fine-scale versus overall enamel distribution. On the one hand, unevenly thick enamel at a fine scale, combined with strongly decussated enamel as observed in P. pygmaeus, is expected to increase local resistance to crack propagation. On the other hand, uniformly thick enamel at the overall scale would improve the overall resilience of the enamel in coping with challenging food on a daily basis. Although understanding the effects of ecology on enamel distribution in apes requires further investigation, the results presented in this paper confirm the interest of enamel distribution for taxonomy and phylogeny.

Quality of life following ostomy reversal with purse-string vs linear skin closure: a systematic review

BACKGROUND

The importance of the defunctioning stoma on minimizing anastomotic leak in colorectal surgery is well established. However, a defunctioning stoma can substantially impact on quality of life (QoL). Circumferential purse-string approximation (PSA) and linear skin closure (LSC) are the most commonly performed surgical technique for reversal of stoma. The aim of this review was to systemically review and meta-analyze available randomized controlled trials (RCTs) comparing PSA and LSC.

METHODS

An electronic systematic search using MEDLINE databases (PubMed, EMBASE, and Web of Science) of RCTs comparing PSA and LSC was performed. Eight RCTs totalling 647 patients met the inclusion criteria and were included in this meta-analysis.

RESULTS

Patient's satisfaction is significantly lower in PSA group during the first postoperative week, but it sharply improves afterwards and no difference were noted at 1 and 6 months between the two groups. Relative risk (RR) of developing a SSI is significantly lower in PSA compared to LSC group (RR 0.16 95% CI 0.09; 0.30; p = 0.0001), whereas incisional hernia (RR 0.53 95% CI 0.08; 3.53; p = 0.512), operative time (MD - 0.06 95% CI - 0.30; 0.17; p = 0.593), and hospital stay (MD - 0.09 (95% CI - 0.29-0.11; p = 0.401) remain similar.

DISCUSSION

QoL was similar in both patients groups after the first postoperative week. PSA significantly reduced SSI rate. No difference was observed in incisional hernia rate, operative time, or length of hospital stay.