Ecological assessment of an intermittent Mediterranean river using community structure and function: evaluating the role of different organism groups

1. Reliable lotic ecological monitoring requires knowledge of river typology, environmental factors, the effect of stressors known here as ‘pressures’ and appropriate indicators of anthropogenically induced change. We sampled benthic macroinvertebrate, fish, bird and macrophyte communities along an intermittent Mediterranean river and analysed community structure (relative abundance) and function (metrics) relative to environmental and pressure gradients in order to identify suitable indicator group(s) for future monitoring and mitigation programmes. 2. Principal components analysis revealed that scale‐dependent longitudinal differences in valley form separated narrower higher lying sites and tributaries with good quality habitats from more open degraded sites lower down the river continuum on a small floodplain and large scale pressures describing changes in land use related to agriculture with associated physical bankside and channel impacts. 3. Forward selection of variables in redundancy analysis (RDA) showed that reach scale environmental variables were selected more frequently than pressure variables for each organism group. Altitude and pH were highly redundant within and between groups, indicating essentially longitudinal structural and functional distribution patterns. Redundancy was far lower between selected pressure variables, but single or no pressure variables were retained for some organism groups indicating poor association of functional data, in particular, with the identified pressures. All RDA results indicated a longitudinal pH gradient, highlighting the combined effect of multiple environmental and pressure based mechanisms on organism groups. 4. Large, mobile organisms such as fish and birds provided a reliable link between organism structure and function, environmental factors and physical disturbance of the channel, bankside and wider river corridor. Benthic macroinvertebrate and macrophyte structural data revealed distribution patterns in relation to water velocity, a key parameter for developing appropriate compensation measures. 5. Results clearly show the importance of assessing patterns of both functional and structural change across multiple organism groups in order to identify typologically appropriate links with complex environmental and pressure gradients and develop and implement appropriate monitoring systems.     

Comparison of two sampling methods for domestic populations of Triatoma infestans in north-west Argentina

Abstract. In mud-and-thatch houses of Santiago del Estero Province, northwest Argentina, where no insecticides had been sprayed officially to control domestic infestations of the Chagas disease vector Triatoma infestans (Klug) (Hemiptera: Reduviidae), two knockdown (KD) insecticidal collection procedures were compared with the standard flush-out (FO) method for sampling T. infestans. Bugs were collected by FO using 0.2% tetramethrin in bedrooms of (1) 41 houses of Amama village employing 1 man-hour of capture effort per house, and (2) 19 houses of Trinidad and Mercedes villages employing 4 man-hours/house. From the same houses, 2-5 days after the manual FO collection, bugs were collected by KD indoor-spraying of deltamethrin 25mga.i./m² in Amama, or burning of one γ-HCH (=γ-BHC) fumigant tablet 3.1g of γ-isomer) per bedroom in Trinidad and Mercedes. The majority of infestations were detected by both methods, the proportion of positive houses being 81% at Amama and 95% at the other villages. Although the FO method was more sensitive, at least because it was applied first, the KD method detected infestations in 25% of houses where bugs were not found by FO. Bug densities estimated by FO or by subsequent KD in each house were significantly correlated: r = 0.795 for deltamethrin; r= 0.882 for y-HCH. Compared with FO collections of T.infestans large stages, i.e. adults plus fourth and fifth instar nymphs, the KD catch averaged 0.88x with deltamethrin and 0.57× with γ-HCH, regardless of the apparent population density of bugs per house. However, the KD method has practical advantages of speed and standardization.     

Biochemical Changes in Cultures of Nectria galligena during the Autolytic Phase of Growth

Some biochemical changes occurring in cultures of Nectria galligenaduring its autolytic phase of growth have been investigated.In nitrate-grown and autolysed cultures of this fungus the degreeof autolysis amounted to 57 per cent. The amount of myceliallipids decreased continuously with the age of the culture. Totalmycelial nitrogen did not substantially change within the first50 days of autolysis. The constancy in the amount of bound aminoacids released from mycelium of Nectria galligena strongly suggeststhat mycelial protein are not affected by autolysis.     

ORCADIAN COMPONENTS IN THE DAILY ACTIVITY OF HELIX LUCORUM L. FROM NORTHERN GREECE

The nocturnal activity of Helix lucorum Linnaeus has a majorcircadian component, normally entrained by photoperiod, anda second, slower circadian oscillator is also present. (Received 19 March 1986;     

The prevalence and correlates of DSM-IV disorders in the Iraq Mental Health Survey (IMHS)

Data on the prevalence and correlates of anxiety, mood, behavioral, and substance disorders are presented from a 2007-8 national survey of the Iraq population, the Iraq Mental Health Survey (IMHS). The IMHS was carried out by the Iraq Ministry of Health in collaboration with the Iraq Ministry of Planning and the World Health Organization (WHO) World Mental Health (WMH) Survey Initiative. Interviews were administered to a probability sample of Iraqi household residents by trained lay interviewers. The WHO Composite International Diagnostic interview (CIDI) was used to assess DSM-IV disorders. The response rate was 95.2%. The estimated lifetime prevalence of any disorder was 18.8%. Cohort analysis documented significantly increasing lifetime prevalence of most disorders across generations. This was most pronounced for panic disorder and post-traumatic stress disorder, with lifetime-to-date prevalence 5.4-5.3 times as high at comparable ages in the youngest (ages 18-34) as oldest (ages 65+) cohorts. Anxiety disorders were the most common class of disorders (13.8%) and major depressive disorder (MDD) the most common disorder (7.2%). Twelve-month prevalence of any disorder was 13.6%, with 42.1% of cases classified mild, 36.0% moderate, and 21.9% serious. The disorders most often classified serious were bipolar disorder (76.9%) and substance-related disorders (54.9%). Socio-demographic correlates were generally consistent with international epidemiological surveys, with the two exceptions of no significant gender differences in mood disorders and positive correlations of anxiety and mood disorders with education. Only 2.2% of IMHS respondents reported receiving treatment for emotional problems in the 12 months before interview, including 23.7% of those with serious, 9.2% with moderate, and 5.3% with mild disorders and 0.9% of other respondents. Most healthcare treatment, which was roughly equally distributed between the general medical and specialty sectors, was of low intensity. Further analyses of barriers to seeking treatment are needed to inform government efforts to expand the detection and treatment of mental disorders     

Identification of C3 Acceptors Responsible for Complement Activation in Crithidia fasciculata1

Crithidia fasciculata, an insect trypanosomatid is readily lysed by normal human serum at concentrations as low as 3%. Lysis occurs in the presence of Mg⁺²-EGTA and is antibody independent, indicating that the alternative pathway of complement activation is involved. Analysis of [¹³¹I]C3 deposition on C. fasciculata cells using C8-deficient serum, revealed that about 4 times 10⁵ C3 molecules bound to each cell. Most of the C3 was bound to cells as C3b, part of it forming high molecular weight complexes, which could be dissociated by methylamine treatment at alkaline pH. To characterize the C3 acceptors on C. fasciculata, surface-iodinated cells were incubated with C8D or heat-inactivated serum, extracted and immunoprecipitated with anti-C3 or anti-arabinogalactan antisera. Analysis of the immunoprecipitated material on SDS gels showed high-molecular weight components, which disappeared after methylamine treatment, giving rise to a component of 200 kDa molecular size. This 200-kDa component corresponded to a purified arabinogalactan complex, which was immunoprecipitated from labeled cell extracts, without incubation with C8D, using anti-arabinogalactan antibodies. These results suggest that the arabinogalactan glycoconjugate is a C3 acceptor in C. fasciculata during complement activation. Purified arabinogalactan complexes were able to inactivate C3 in vitro. Solubilization in KOH to cleave the peptide moiety rendered it unable to inactivate C3. Apparently, the aggregated state of the purified arabinogalactan component at the cell surface is important for C3 deposition and activation.     

Morphological and biochemical variation in populations of Dugesia (G.) tigrina (Turbellaria, Tricladida, Paludicola) from the western Mediterranean: biogeographical and taxonomical implications

Dugesia (Girardia) tigrina is a Nearctic freshwater triclad native to North America, now amply distributed in most European countries as the result of a reportedly unique introduction into north-west Europe early this century and its dispersal southwards and eastwards in the last decades. All European populations described so far are externally spotted, with a pigmented pharynx, and, apart from two sexual populations recently described in England, they are fissiparous. This uniformity contrasts with the variability reported in its native area, thus supporting the hypothesis of a single introduction. However, thorough morphological, karyological and biochemical comparative studies of European populations have never been properly done.
We have undertaken such a study comparing 24 populations present in a restricted area of the western Mediterranean. The results show an unexpectedly ample variation in external and pharyngeal pigmentation patterns, the presence of sexually reproducing populations, and ample variation in their biochemical patterns as revealed by isoelectric-focusing. This is an indication that European Dugesia (G.) tigrina is far more diverse than previously thought, suggesting that several, independent introductions from its native area have recently occurred, and the implications of these findings in biogeographical and taxonomic terms are discussed.     

Myxosoma cerebralis (Myxozoa: Myxosporea) Etiologic Agent of Salmonid Whirling Disease Requires Tubificid Worm (Annelida: Oligochaeta) in its Life Cycle

Studies of the life cycle of Myxosoma cerebralis showed that development of infectivity did not occur endogenously but that the spore “aging” process required participation of an aquatic tubificid oligochaete. Data suggestive of such involvement were derived from trials in which spores were “aged” in an array of inert, sterilized, pasteurized, or natural aquatic substrates and from examination of aquatic soils from trout hatcheries in which whirling disease was epizootic. The role of the aquatic oligochaete was confirmed two ways. First, signs of whirling disease developed, and M. cerebralis spores were produced in young rainbow trout (Salmo gairdneri) that had been fed oligochaetes harvested from pond soil taken from two hatcheries where whirling disease was epizootic. Second, when containers of pasteurized soil were populated with four genera of oligochaetes–Aeolosoma, Dero, Stylaria, or Tubifex– from a biological supply house, or with tubificid worms from trout hatcheries free of whirling disease, and then seeded with M. cerebralis spores and “aged” for 4 months, whirling disease occurred only in trout held with Tubifex and with hatchery tubificids.