Fluctuations of grass pollen content in the atmosphere of East Perugia and meteorological correlations (year 1989)

Summary Gramineae pollination from a pollen monitoring station located in the eastern suburb of Perugia and meteorological correlations are reported. The data refers to the year 1989. Grass pollen peak pollination was from May to July; in this period the influence of relative humidity and of temperature on pollen concentration was very high. Phenological observations, to identify the time of maximum stamen extension in the most common genera in the area, are also reported. During the period of investigation the counts of pollen grains over four-hour periods showed a regular diurnal rhythm with peaks of concentration in the four-hour period 16.00–20.00. Aerosporological data and meteorological data related to four-hour periods were correlated following different criteria.     

An “orientation sphere” visualization for examining animal head movements

1. Animal behavior is elicited, in part, in response to external conditions, but understanding how animals perceive the environment and make the decisions that bring about these behavioral responses is challenging.
2. Animal heads often move during specific behaviors and, additionally, typically have sensory systems (notably vision, smell, and hearing) sampling in defined arcs (normally to the front of their heads). As such, head‐mounted electronic sensors consisting of accelerometers and magnetometers, which can be used to determine the movement and directionality of animal heads (where head “movement” is defined here as changes in heading [azimuth] and/or pitch [elevation angle]), can potentially provide information both on behaviors in general and also clarify which parts of the environment the animals might be prioritizing (“environmental framing”).
3. We propose a new approach to visualize the data of such head‐mounted tags that combines the instantaneous outputs of head heading and pitch in a single intuitive spherical plot. This sphere has magnetic heading denoted by “longitude” position and head pitch by “latitude” on this “orientation sphere” (O‐sphere).
4. We construct the O‐sphere for the head rotations of a number of vertebrates with contrasting body shape and ecology (oryx, sheep, tortoises, and turtles), illustrating various behaviors, including foraging, walking, and environmental scanning. We also propose correcting head orientations for body orientations to highlight specific heading‐independent head rotation, and propose the derivation of O‐sphere‐metrics, such as angular speed across the sphere. This should help identify the functions of various head behaviors.
5. Visualizations of the O‐sphere provide an intuitive representation of animal behavior manifest via head orientation and rotation. This has ramifications for quantifying and understanding behaviors ranging from navigation through vigilance to feeding and, when used in tandem with body movement, should provide an important link between perception of the environment and response to it in free‐ranging animals.

     

Carbonic anhydrase inhibition blocks skeletogenesis and echinochrome production in Paracentrotus lividus and Heliocidaris tuberculata embryos and larvae

Carbonic anhydrases (CAs) are a family of widely distributed metalloenzymes, involved in diverse physiological processes. These enzymes catalyse the reversible conversion of carbon dioxide to protons and bicarbonate. At least 19 genes encoding for CAs have been identified in the sea urchin genome, with one of these localized to the skeletogenic mesoderm (primary mesenchyme cells, PMCs). We investigated the effects of a specific inhibitor of CA, acetazolamide (AZ), on development of two sea urchin species with contrasting investment in skeleton production, Paracentrotus lividus and Heliocidaris tuberculata, to determine the role of CA on PMC differentiation, skeletogenesis and on non‐skeletogenic mesodermal (NSM) cells. Embryos were cultured in the presence of AZ from the blastula stage prior to skeleton formation and development to the larval stage was monitored. At the dose of 8 mmol/L AZ, 98% and 90% of P. lividus and H. tuberculata embryos lacked skeleton, respectively. Nevertheless, an almost normal PMC differentiation was indicated by the expression of msp130, a PMC‐specific marker. Strikingly, the AZ‐treated embryos also lacked the echinochrome pigment produced by the pigment cells, a subpopulation of NSM cells with immune activities within the larva. Conversely, all ectoderm and endoderm derivatives and other subpopulations of mesoderm developed normally. The inhibitory effects of AZ were completely reversed after removal of the inhibitor from the medium. Our data, together with new information concerning the involvement of CA on skeleton formation, provide evidence for the first time of a possible role of the CAs in larval immune pigment cells.     

Oxygen: a master regulator of pancreatic development?

Beyond its role as an electron acceptor in aerobic respiration, oxygen is also a key effector of many developmental events. The oxygen‐sensing machinery and the very fabric of cell identity and function have been shown to be deeply intertwined. Here we take a first look at how oxygen might lie at the crossroads of at least two of the major molecular pathways that shape pancreatic development. Based on recent evidence and a thorough review of the literature, we present a theoretical model whereby evolving oxygen tensions might choreograph to a large extent the sequence of molecular events resulting in the development of the organ. In particular, we propose that lower oxygenation prior to the expansion of the vasculature may favour HIF (hypoxia inducible factor)‐mediated activation of Notch and repression of Wnt/β‐catenin signalling, limiting endocrine cell differentiation. With the development of vasculature and improved oxygen delivery to the developing organ, HIF‐mediated support for Notch signalling may decline while the β‐catenin‐directed Wnt signalling is favoured, which would support endocrine cell differentiation and perhaps exocrine cell proliferation/differentiation.     

Differential response to hepatic differentiation stimuli of amniotic epithelial cells isolated from four regions of the amniotic membrane

Human Amniotic Epithelial Cells (hAEC) isolated from term placenta are a promising source for regenerative medicine. However, it has long been debated whether the hAEC population consists of heterogeneous or homogeneous cells. In a previous study, we investigated the characteristics of hAEC isolated from four different regions of the amniotic membrane finding significant heterogeneity. The aim of this study was to evaluate the hepatic differentiation capability of hAEC isolated from these four regions. Human term placentae were collected after caesarean section and hAEC were isolated from four regions of the amniotic membrane (R1-R4, according to their relative distance from the umbilical cord) and treated in hepatic differentiation conditions for 14 days. hAEC-derived hepatocyte-like cells showed marked differences in the expression of hepatic markers: R4 showed higher levels of Albumin and Hepatocyte Nuclear Factor (HNF) 4α whereas R1 expressed higher Cytochrome P450 enzymes, both at the gene and protein level. These preliminary results suggest that hAEC isolated from R1 and R4 of the amniotic membrane are more prone to hepatic differentiation. Therefore, the use of hAEC from a specific region of the amniotic membrane should be taken into consideration as it could have an impact on the outcome of therapeutic applications.