The “Flexi-Chamber”: A Novel Cost-Effective In Situ Respirometry Chamber for Coral Physiological Measurements

Coral reefs are threatened worldwide, with environmental stressors increasingly affecting the ability of reef-building corals to sustain growth from calcification (G), photosynthesis (P) and respiration (R). These processes support the foundation of coral reefs by directly influencing biogeochemical nutrient cycles and complex ecological interactions and therefore represent key knowledge required for effective reef management. However, metabolic rates are not trivial to quantify and typically rely on the use of cumbersome in situ respirometry chambers and/or the need to remove material and examine ex situ, thereby fundamentally limiting the scale, resolution and possibly the accuracy of the rate data. Here we describe a novel low-cost in situ respirometry bag that mitigates many constraints of traditional glass and plexi-glass incubation chambers. We subsequently demonstrate the effectiveness of our novel "Flexi-Chamber" approach via two case studies: 1) the Flexi-Chamber provides values of P, R and G for the reef-building coral Siderastrea cf. stellata collected from reefs close to Salvador, Brazil, which were statistically similar to values collected from a traditional glass respirometry vessel; and 2) wide-scale application of obtaining P, R and G rates for different species across different habitats to obtain inter- and intra-species differences. Our novel cost-effective design allows us to increase sampling scale of metabolic rate measurements in situ without the need for destructive sampling and thus significantly expands on existing research potential, not only for corals as we have demonstrated here, but also other important benthic groups

Comparative Dynamics of Retrograde Actin Flow and Focal Adhesions: Formation of Nascent Adhesions Triggers Transition from Fast to Slow Flow

Dynamic actin network at the leading edge of the cell is linked to the extracellular matrix through focal adhesions (FAs), and at the same time it undergoes retrograde flow with different dynamics in two distinct zones: the lamellipodium (peripheral zone of fast flow), and the lamellum (zone of slow flow located between the lamellipodium and the cell body). Cell migration involves expansion of both the lamellipodium and the lamellum, as well as formation of new FAs, but it is largely unknown how the position of the boundary between the two flow zones is defined, and how FAs and actin flow mutually influence each other. We investigated dynamic relationship between focal adhesions and the boundary between the two flow zones in spreading cells. Nascent FAs first appeared in the lamellipodium. Within seconds after the formation of new FAs, the rate of actin flow decreased locally, and the lamellipodium/lamellum boundary advanced towards the new FAs. Blocking fast actin flow with cytochalasin D resulted in rapid dissolution of nascent FAs. In the absence of FAs (spreading on poly-L-lysine-coated surfaces) retrograde flow was uniform and the velocity transition was not observed. We conclude that formation of FAs depends on actin dynamics, and in its turn, affects the dynamics of actin flow by triggering transition from fast to slow flow. Extension of the cell edge thus proceeds through a cycle of lamellipodium protrusion, formation of new FAs, advance of the lamellum, and protrusion of the lamellipodium from the new base

Lifestyle impact and the biology of the human scrotum

The possession of a scrotum to contain the male gonads is a characteristic feature of almost all mammals, and appears to have evolved to allow the testes and epididymis to be exposed to a temperature a few degrees below that of core body temperature. Analysis of cryptorchid patients, and those with varicocele suggest that mild scrotal warming can be detrimental to sperm production, partly by effects on the stem cell population, and partly by effects on later stages of spermatogenesis and sperm maturation. Recent studies on the effects of clothing and lifestyle emphasize that these can also lead to chronically elevated scrotal temperatures. In particular, the wearing of nappies by infants is a cause for concern in this regard. Together all of the evidence indirectly supports the view that lifestyle factors in addition to other genetic and environmental influences could be contributing to the secular trend in declining male reproductive parameters. The challenge will be to provide relevant and targeted experimental results to support or refute the currently circumstantial evidence.Richard Ivel

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

A taxonomic revision of the genus Pastinaca L. (Umbelliferae)

WOS: 000169781800011A taxonomic revision of the genus Pastinaca L. was carried out with respect to fruit macro- and micro-morphology, anatomy, palynology, and phytochemistry. The study covers the world distribution of the genus, confined to Europe and Asia, except for Pastinaca sativa L. subsp. sativa (parsnip) cultivated all over the world. Pollen studies showed that the pollen of the genus could be described as cerebroid. Three flavonoid compounds were detected in the: genus. Pastinaca is represented with eight species and four subspecies in the world. P. latifolia DC. is regarded as a subspecies of P. sativa

Comparative fruit studies in a group of tribe Peucedaneae (Umbelliferae)

WOS: 000170867200008Comparative fruit studies (macro- and micro-morphology and anatomy) have been undertaken in a group of tribe Peucedaneae (Umbelliferae) (Malabaila Hoffm., Pastinaca L., Heracleum L., Stenotaenia Boiss., Opopanax W.D.J. Koch, and Grafia Rchb.). A multivariate analysis was carried out using Simple Matching Coefficient and UPGMA (unweighted pair group method using arithmetic averages) and WPGMA (weighted pair group method using arithmetic averages) clustering methods. Two types of dorsal mericarp, surface and margin sufaces were detected: (1) reticulate with a smooth surface, (2) reticulate with a striate surface. On the dorsal surface of the mericarps, three hair shapes and four hair surface types were seen. These hairs are treated as having systematic significance. For instance, a very short triangular hair with a papillose surface is unique to Pastinaca. The shapes of the mericarp and mericarp apex at the base of stylopodium are significant features for generic delimitation. Malabaila is distinguished by its cordate-obovate mericarp with mericarp apex curved at stylopodium base. Anatomical features, such as the number of the vittae on the dorsal surface, the length of the mericarp wing neck and margin, are significant. The genera Stenotaenia and Opopanax are characterized by having many vittae on the dorsal and commissural. surfaces

Flavonoid patterns in Convolvulus L., (Convolvulaceae) species from Morocco

WOS: 000178924500011This study was undertaken to document the distribution of chemical components and determine whether phytochemical characters support the delimitation of the taxa in the genus Convolvulus L., from Morocco. Twenty taxa from the genus were investigated for their flavonoid aglycone constituents. The flavonols quercetin, kaempferol and isorhamnetin, the flavone luteolin and the hydroxycoumarin cichoriin were identified. It was seen that the aglycone pattern is useful for the delimitation of some species in the genus and correlate with morphological features. The flavonoid glycosides identified from Convolvulus mazicum were isorhamnetin 3-glucoside, quercetin 3-glucoside and 3-galactoside and luteolin 5-glucoside