Inhibition vs. enhancement of the nitrate-induced phototransformation of organic substrates by the OH scavengers bicarbonate and carbonate

Contrary to common expectations, the hydroxyl scavengers, carbonate and bicarbonate, are able to enhance the phototransformation by nitrate of a number of substituted phenols. Carbonate and bicarbonate, in addition to modifying the solution pH, are also able to induce a considerable formation of the carbonate radicals upon nitrate photolysis. The higher availability of less-reactive species than the hydroxyl radical would contribute to substantially enhance the photodegradation of the phenols/phenolates that are sufficiently reactive toward the carbonate radical. This phenomenon has a potentially important impact on the fate of the relevant compounds in surface waters. In contrast, the degradation of compounds that are not sufficiently reactive toward CO₃^−• is inhibited by carbonate and bicarbonate because of the scavenging of ^•OH.     

Knowledge integration at the edge of technology: On teamwork and complexity in new turbine development

This paper takes an empirical point of departure in the development of a new steam turbine. Project work here relied on a process of iteration between a small core group of team members with extensive experience and team members with less of that currency. In this project, the core group had a major integrative role, whereas other team members were mainly responsible for the specific tasks assigned to them. Quite a few of the latter category felt uneasy about their role and felt ‘decoupled’ from the project. In our analysis we use the Teamwork Quality (TWQ) construct proposed by Hoegl and Gemuenden (2001). In conclusion, our findings suggest that in highly complex projects of this type, team-based knowledge integration need not presuppose equality of participation and we introduce the notion of a Segregated Team to account for these findings.     

Inter-annual variations of planktonic food webs in the northern Adriatic Sea

The temporal dynamics of microphytoplankton, microzooplankton and mesozooplankton were monitored over 37 months in the Adriatic Sea in order to identify alterations in the plankton structures, which can lead to, or enhance the production of macro-aggregates, that affected the entire northern basin in summers 2000 and 2002, and to assess any negative effects of mucilage on plankton temporal patterns. Samples were collected monthly, from June 1999 to July 2002, on three transects at 9 stations across the northern and central Adriatic Sea. Besides the high year-to-year variations in abundances and taxonomical composition, plankton communities only showed a clear seasonal succession during 2001, when since April a grazing food web developed and was able to control large sized phytoplankton increase. In spring-summer 2000 and 2002 consumer abundances remained quite low and the dominant mesozooplankton summer species (Penilia avirostris) did not reach its usual summer maximum. The lack of an efficient top control was more evident on the northernmost transect, where generally grazing food web prevails over the microbial one. A large part of the microphytoplankton blooms, although not particularly intense, was exported to the bottom in the particulate phase, where it was processed by bacteria, enhancing the production of refractory dissolved material.     

Occurrence of enteric viruses and faecal indicators in submarine groundwater discharges in the coastal environment of the Mexican Caribbean

The occurrence of faecal microorganisms such as total coliforms (TCs), Escherichia coli (E. coli), coliphages (somatic and F+ specific) and the genomes of faecal viruses: human adenovirus (HAdV), norovirus (NoV) genogroup I (GI) and II (GII), enterovirus (EV), aichi virus (AiV) and Pepper mild mottle virus (PMMoV), was explored in submarine groundwater discharges (SGDs) in the Mexican Caribbean. Ultra-filtrated water samples were subjected to nucleic acid extraction and real-time quantitative polymerase chain reaction (PCR). Results showed the presence of TC bacteria at all sites, whereas the detection of E. coli occurred only during the dry season. Coliphages occurred during the rainy and dry seasons, with concentrations ranging from 10 to 2560 plaque forming units (PFU/100 ml). HAdV and AiV were detected in 50% and 41% of the samples, at concentrations ranging from 10² to 10⁴ genome copies per litre (GC/L) and from 10² to 10⁶ GC/L, respectively. NoV GI and II were detected in 25% and 16% of the samples, at concentrations of 10¹ GC/L and 10²–10³ GC/L, respectively. PMMoV was detected in 50% of the samples at concentrations ranging from 10¹ to 10³ GC/L. The EV genomes were not detected. These findings demonstrate that faecal microorganisms can be transported through SGDs in the Mexican Caribbean, potentially contributing to human health risks for recreation.     

Review of current state of knowledge of microcystin and its impacts on fish in Lake Victoria

Microcystins are part of algal toxins produced intracellularly within algal cells, being in the family of hepatotoxic cyclic peptides from various species of blue‐green algae. Blue‐green algae are widely abundant in many equatorial eutrophic lakes, including Lake Victoria, with microcystin mainly from cyanobacterial blooms released into the water column, with different effects along the aquatic ecosystem trophic levels. Depending on the length of exposure and exposure route, microcystin effects on fish can include embryonic hatching perturbations, reduced survival and growth rates, changes in behavior, osmoregulation, increased liver activities and heart rates, as well as histopathological effects. While bioaccumulation is confirmed among fish, biomagnification along food webs is debatable. Lake Victoria the second largest freshwater lake in the world, and the source of livelihoods to millions reported near the gulf and shore MCs of 190 ± 51 to 543 ± 26 ng MC/g DW, respectively. Little is known, however, on the effects of microcystin on the Lake Victoria fishery and, ultimately, on the human population against the WHO recommended human microcystin intake levels of 0.04 µg/kg, thereby being the basis for this review.     

Study of the Expression and Function of Calcium-Sensing Receptor in Human Skeletal Muscle

Skeletal muscle has an outstanding capacity for regeneration in response to injuries, but there are disorders in which this process is seriously impaired, such as sarcopenia. Pharmacological treatments to restore muscle trophism are not available, therefore, the identification of suitable therapeutic targets that could be useful for the treatment of skeletal reduced myogenesis is highly desirable. In this in vitro study, we explored the expression and function of the calcium-sensing receptor (CaSR) in human skeletal muscle tissues and their derived satellite cells. The results obtained from analyses with various techniques of gene and protein CaSR expression and of its secondary messengers in response to calcium (Ca²⁺) and CaSR drugs have demonstrated that this receptor is not present in human skeletal muscle tissues, neither in the established satellite cells, nor during in vitro myogenic differentiation. Taken together, our data suggest that, although CaSR is a very important drug target in physiology and pathology, this receptor probably does not have any physiological role in skeletal muscle in normal conditions.     

Frequency of heavy episodic drinking among nonfatal injury patients attending an emergency room

This study investigated the relationship between frequency of heavy episodic drinking and nonfatal injury in four categories: environment, external cause, diagnosis, and activity at the time of injury. Data were collected over 18 months at the emergency room facility of a Swedish hospital. Injury patients aged 18-70 years answered an alcohol screening questionnaire. Heavy episodic drinking was measured as drinking six glasses (72 g alcohol) or more per occasion, for both males and females. A total of 2211 patients were enrolled in the study (79.5% completion rate). Demographic and drinking characteristics for the patients were compared to those of the general population, data for which were derived from a population-based survey. The proportion of people who reported heavy episodic drinking once a month or more was nearly twice as large among the injury patients as in the general population. However, age and sex outweighed heavy episodic drinking as risk factors for most injury types. There were 11 significant associations between frequency of heavy episodic drinking and injury types in the four injury categories, yet no linear trends of increased likelihood of injury with increased frequency of heavy episodic drinking could be discerned.