Acaricidal activity of limonene, limonene oxide and beta-amino alcohol derivatives on Rhipicephalus (Boophilus) microplus

Limonene, limonene oxide and eight beta-amino alcohol derivatives obtained by synthesis were investigated for the effect on egg hatchability and mortality rates of newly hatched larvae of the cattle tick Rhipicephalus (Boophilus) microplus. At the doses between 10mug/ml and 2.5mug/ml all the compounds were highly lethal to the larvae and some of them showed activity at lower concentrations. The effect on the eggs hatchability was observed in all the treatments.     

Root dynamics of peach trees submitted to partial rootzone drying and continuous deficit irrigation

The root dynamics of young early-season peach trees (Prunus persica L. Batsch, cv. Flordastar) were studied during one growing season. The trees were submitted to three drip irrigation treatments: T1 (control) irrigated at 100% of the estimated crop evapotranspiration (ETc) requirements, T2 (continuous deficit) irrigated at 50% ETc and T3 (partial rootzone drying, PRD, treatment), alternating irrigation from one half to the other every 2–3 weeks. Root length was measured frequently using minirhizotrons and a circular-vision scanner. Overall, root length density was reduced by ≈73% in the continuous deficit irrigated treatment and by ≈42% in the T3 treatment with respect to the well irrigated treatment. A roughly similar amount of water was applied in both deficit irrigated treatments (44 and 56% of T1, for T2 and T3, respectively), but the continuous deficit irrigation applied to both sides of the root system in T2 resulted in a greater reduction in root growth than in T3. The dynamics of the root growth were similar in the three treatments. In general, root growth declined during the fruit growth period and increased after harvest, reaching its peak in mid July. By late July, root growth had declined again, and an alternating pattern of growth between the aerial and root parts of the tree was observed. Roots were mostly located in the upper 0.55 m of soil and were particularly concentrated at 0.40–0.55 m. More than 88% of these roots were very thin, with diameters of <0.5 mm. The study looks at the impact of deficit irrigation on the phenological processes related with root growth, and will help in making decisions concerning fertigation in areas with scarce water resources where deficit irrigation strategies are considered desirable.     

A New Virus of Longan (Euphoria longana Lam.) in Hong Kong

Abstract

Rattus norvegicus occurs in Singapore, with several other commensal rodent species. This preliminary study examined populations and a possible control method in urban and semi-urban areas. Commensal rats are generally undesirable, and a possible role for R. norvegicus in spreading any introduced plague is a particular worry. Populations were examined by catch, mark, release (CMR) and by removal (regression) methods. Species and numbers indicated by removal were—R. norvegicus (57.4, 31.9 and 48.5/ha in different trials), R. exulans (37.2/ha) and Mus musculus (8.3/ha). There were indications that these figures were very considerable underestimates; a Lincoln Index, using recovered dead rats (after poisoning in a CMR Plot) as the second sample, estimated R. norvegicus at 985/ha (i.e. in a ca 0.6 ha plot—618 ± 694); the recovery of only three out of 32 marked rats, and the presence of many dead but uncollected rats, even though more than the number estimated by removal was picked up in the plot (58) Banana, coconut and dried fish cage baits all trapped rats. Maize cakes were not worth the extra labour. Analysis of catch by trap position suggested that R. exulans is more common upon roofs, R. norvegicus was absent from a semi-rural environment in which R. r. diardii was common. In a control programme, wax-bound maize-based anticoagulant baits were used—distributed at 91/ha, replaced, at 2—4 day intervals if accepted, to total nine rounds and 818 baits/ha at a cost of M$21.00. Acceptance of baits was high initially, and further trapping showed that reasonable control had been obtained. This method seems more appropriate to the conditions than the permanent baiting stations used in temperate areas, because of the lack of discrete points in sewers etc., the disrupting influence of frequent tropical storms, rapid deterioration of baits, and competition from other animals, particularly ants. Drawbacks include the danger to non-target animals from the baits and the temporary stench of dead rats.     

Spontaneous pneumopericardium in a dog with bronchopulmonary disease complicated by pyothorax and pneumothorax

Spontaneous pneumopericardium is a rare condition consisting of pericardial gas in the absence of iatrogenic or traumatic causes; it has been described secondary to pneumonia, lung abscess, and bronchopulmonary disease. This report describes a case of spontaneous pneumopericardium in a dog presenting with dyspnea secondary to pyopneumothorax complicating a bronchopulmonary disease.     

Immunohistochemical identification and localization of orexin A and orexin type 2 receptor in the horse gastrointestinal tract

The aim of the present study was to investigate the presence and the distribution of cells containing orexin A and orexin type 2 receptor in the horse stomach and gut, by means of immunohistochemical techniques.Orexin A was identified in the stomach fundic and pyloric regions and in the duodenum. In the same stomach regions, a large subset of orexin A-positive cells also showed orexin type 2 receptor-like immunoreactivity. Moreover, in the duodenum, many of them, seemed to store serotonin.Characteristically, enteric neurons or ganglia also displayed orexin A and, sometimes, orexin type 2 receptor immunoreaction.Orexin A and orexin type 2 receptor immunoreactivity was also found in the nerve fibers in the enteric submucosal layer.Our results, together with data present in the literature, could contribute to the understanding of complex mechanisms regulating the horse gut functionality that are depending very likely on the consequence of the co-operation of both a central and a peripheral control.     

New data on three molecular markers from different cellular genomes in Mediterranean accessions reveal new insights into phylogeography of <Emphasis Type="Italic">Pisum sativum</Emphasis> L. subsp. <Emphasis Type="Italic">elatius</Emphasis> (Bieb.) Schmalh.

Twelve accessions classified as Pisum sativum subsp. elatius, mostly from West and Central Mediterranean, were analysed for three markers from different cellular genomes: rbcL (plastid genome), coxI (mitochondrial genome) and SCA (nuclear genome). Based on geographical distribution of their allele combinations analysed in this and the earlier study, we suggest a putative history of wild representatives of P. sativum. The ancestor of this species belonged to lineage A (coxI+, rbcL+, SCA ^f ); it appeared in East Mediterranean, then spread westward most probably during one of the Pleistocene coolings when the sea was smaller, so that representatives of lineage A remained in the Eastern Mediterranean and on the islands of Sicily and Menorca. Mutation leading to the loss of the restriction site for PsiI in coxI−, gave rise to lineage C (coxI−, rbcL+, SCA ^f ) which spread widely in the Mediterranean and is now found in France, Greece and Ethiopia. Mutation leading to rbcL− gave rise to lineage D (coxI−, rbcL−, SCA ^f ), now found in Egypt (P. sativum subsp. jomardii) and Spain. Mutational transition of SCA ^f to SCA ^s most probably took place in North-Eastern Mediterranean since the resulting lineage B (coxI−, rbcL−, SCA ^s ) now occupies the Tauro-Caucasian area. In Asia Minor and North Israel, line B met the ancestral line A so that both lines coexist there presently. The lineage B gave rise to the cultivated P. sativum subsp. sativum.     

Primary immune-mediated hemolytic anemia in 19 cats: diagnosis, therapy, and outcome (1998-2004)

Immune-mediated hemolytic anemia (IMHA) occurs less frequently in cats than in dogs. The value of the Coombs' test (CT) has been questioned, but detailed surveys of its use are lacking. The objective of this study was to describe 19 cats with primary IMHA (pIMHA) and to examine the diagnostic value of the direct CT. The CT was performed in 92 cats; it was negative in 5 healthy, in 9 sick nonanemic, and in 55 cats with different types of anemia. The CT was positive in 18 anemic cats (2 feline leukemia virus (FeLV) positive, 1 with cholangiohepatitis, 15 with no underlying disease). Moreover, agglutination persisted after saline washing in 5 anemic cats (1 lymphoma, 4 pIMHA). Inclusion criteria for pIMHA were a positive CT (15) or persistent agglutination (4), and the exclusion of other diseases. The age of the 19 cats ranged from 0.5 to 9 years (median, 2 years); male cats were overrepresented. The PCV on admission was 6-22% (median, 12%). The anemia was nonregenerative in 11 cats. Additional abnormal laboratory results were leukocytosis (2), lymphocytosis (6), hyperbilirubinemia (13), hyperglobulimemia (10), and increased liver enzyme activities (10). Initial treatment consisted of blood transfusions (10), crystalloids (11), prednisolone (19), antibiotics (19), and H2-blockers (11). Four of 17 cats were euthanized 9, 63, 240 and 2,160 days after initial presentation (mortality rate, 23.5%). Relapses were reported in 5 of 16 cases (31%). Thus, pIMHA appears to occur more frequently than recognized previously, with a more favorable prognosis in cats than in dogs. The CT was useful in identifying immune-mediated pathogenesis.