686 research outputs found
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Biology and feeding habits of pleocoma larvae (Coleptera : Scarabaeidae) in western Oregon coniferous forest
Food habits and biology of five species of Pleocoma larvae were
studied at a dozen forested sites in western Oregon between May 1960
and December 1961.
First instar Pleocoma hatch in late summer and moult to second
instars in early fall. Second and subsequent instars moult annually
between mid-summer and early fall. Larvae appear to go through
more than nine instars pupating after the seventh, in the upper 20
inches of soil, in mid-summer. Male larvae outnumber females by
about 30 percent.
Larvae move through the soil primarily by use of the mandibles.
This movement can exceed a rate of four inches a day.
Larval populations varied from none to 4.4 larvae per square
foot and were distributed between two and 44 inches in depth. Soil
temperatures and soil moisture influenced most larvae at some sites
to leave the upper 16 inches of soil during the summer. At other
sites, however, a shallow silicate clay hardpan influenced larvae to
remain at shallow depths throughout the year. A fungus disease
killed from five to more than 20 percent of the larvae in some areas.
Dipterous predators killed some larvae.
Coniferous roots comprise the major part of the larval diet
throughout most of the year, being found exclusively in 86 percent
of the larvae. Thirty percent of the roots in the guts were definitely
identified as Douglas-fir, the predominant conifer at the sites of
the collections. Larvae preferred smaller roots, mostly smaller
than 2mm, many of them mycorrhizal rootlets. A few larvae merely
girdled the roots, stripping the bark leaving the xylem in the soil.
Most larvae, however, severed and consumed the entire root.
Larvae either severed and ingested intact root segments or gnawed
on root ends masticating them into very fine pieces before ingestion.
Except for last instar larvae, usually at shallower depths, and
first stage larvae, neither of which appeared to feed on roots, all
other larval stages at all depths were feeding on roots throughout
the year, except during the moulting period. The cessation of root
feeding extended over about a four-month moulting period from
June to September, inclusive. The moulting period varied somewhat
between species. Most larvae consumed the exuvia. Some soil,
probably less than five percent by volume, was ingested.
Other material tentatively identified in larval guts was: remains
of fungal hyphae, cast ventricular epithelium, gregarine parasites, and bacteria.
Pleocoma larvae do not appear to be serious forest pests in old-growth and advanced second-growth coniferous forests because of the
generally low and scattered larval populations. In newly-established
forests, however, Pleocoma larvae are a potential pest as one or
two feeding larvae can kill a small tree. Only further studies in regenerated
areas will determine their role in these cut-over and reestablished
forests
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The effect of cold temperatures on the length of diapause of the spruce budworm (Choristoneura fumiferana (Clem.)
Electricity from Wood: A Wood Quality and Energy Efficiency Approach to Small Scale Pyro-gasification
AbstractThe global demand for renewable energy in the last years is facing innovations like the co-generation of electricity and heat from wooden industrial residues and biomass. Wood gasification is a very promising technique for conversion of wood chemical energy into thermal energy and into electricity. A new generation of small scale, moderately priced and easy to install pyro-gasification plants became available on the market, being an opportunity for the SMEs. These systems are also characterized by a remarkable operational easiness and great versatility in the type of used biomass, which can range from industrial residues (sawdust, wood chips...) to biomass of forestry and non-forestry origin. This study performed an extensive testing of a small size pyro-gasification plant capable of producing 30kW of electricity and 30kW of thermal energy, both net to enter in the network of GSE (Energy Services Manager) via the feed-in tariff and in a small district heating network or other uses. The process of pyro-gasification is analyzed in its entirety by a characterization of input biomass, pyro-gasification process monitoring, analysis of the quality of the produced syngas, characterization of residues due to the process (washing water smoke, charcoal...) and verification of the total efficiency. The electric efficiency of the system, from hardwood to syngas to electricity is quantified in being 12%
Participatory analysis of sustainable land and water management practices for integrated rural development in Myanmar
Besides providing reliable water resources for agricultural production, rural development efforts in Myanmar should target rural water security in terms of safe water supply and sanitation, and by mitigating water-related hazards. However, very few studies are available over the status of water-related development in rural areas of the country, and consequently on suitable practical solutions. The present paper describes a participatory workshop undertaken involving 45 rural development officers of the Department of Rural Development (DRD) of the Ministry of Agriculture, Livestock and Irrigation (MOALI), aimed at identifying suitable sustainable land and water management (SLWM) practices to be developed in rural areas of the country. Adoption of water safety plans (WSP), water harvesting, and soil and water bioengineering were strongly supported, while the need for improving water sanitation, especially in the poorest areas, was made evident. Insights of the participatory process confirmed that the poorest regions of Myanmar have also the worst water management structures. The results of the present work can represent baseline information and a needs assessment for future development projects in the country. However, there is a strong need for more studies and reports targeting marginalized rural contexts of Myanmar, to support equitable development
The medieval bronze doors of San Zeno, Verona: combining material analyses and art history
The bronze doors of the Basilica of San Zeno in Verona, Italy, are a special case in art history research. They were made by several workshops during the twelfth century: stylistically, two to three workshops were assumed to pro- duce the metal parts of the door. However, it is still unclear when exactly and if this interpretation can be supported by the chemical composition of the metal. In this research we aimed to verify the art history interpretation by iden- tifying the alloy composition of each individual metal plate. The composition of the supporting wooden structures are discussed. A portable ED-XRF instrument and optical microscopes were used to analyse and document the doors non-invasively. The doors were also photographed to produce high resolution orthophotos and 3D models. We can confirm that the metal parts of the doors were made of leaded tin-bronze as well as leaded brass and mounted on a wooden structure mainly made of spruce and oak wood. Chemically, two/three different groups of alloys have been identified, which can be associated with two or three different workshops, and which largely correspond to the stylistic interpretation
Transient massive hyperlipidaemia in a type 2 diabetic subject
A 50-year-old man, in apparently good health, was referred
to the Lipid Center of San Luigi Gonzaga Hospital,
Orbassano (Turin, Italy), by his primary care physician
(PCP) because clinical tests at the time of blood donation
showed milky plasma with serious hypertriglyceridaemia
(>5000 mg/dl) and hyperglycaemia (381 mg/dl), diagnostic
for diabetes. It was not possible to perform further blood
chemical analyses because hypertriglyceridaemia would
have provided abnormal results. The patient entered the hospital to prevent acute pancreatitis, which is often associated
with severe hypertriglyceridaemi
First report on classical biological control releases of the larval parasitoid Ganaspis brasiliensis against Drosophila suzukii in northern Italy
Current management strategy of the invasive fruit fly Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) exploits different tools but relies mainly on chemical control. In the invaded areas, the local natural enemy community mostly consists of generalist pupal parasitoids unable to control the pest efficiently. Conversely, in the pest native area, there are more specialized sympatric larval parasitoids attacking D. suzukii. Following foreign explorations and quarantine risk assessments, the larval endoparasitoid Ganaspis brasiliensis (Ihering) (Hymenoptera: Figitidae) was selected as the best candidate for classical biological control programs. In 2021, the first ever propagative biocontrol program using a Japanese G1 lineage of G. brasiliensis started in Italy. Here we report the results of the first year of releases in the province of Trento (Northeast Italy), wherein G. brasiliensis was released in 12 locations. Pre- and post-release samplings on fresh and fallen fruits were performed around the release points to assess the recapture rate, the impact of the exotic parasitoid on D. suzukii and its potential interactions with local non-target species. After releases, G. brasiliensis was recovered at 50% of the locations. The exotic parasitoid only emerged from D. suzukii, mostly from fresh fruit still on the plant. Post-overwintering monitoring revealed the presence of a four G. brasiliensis individuals at two release locations
Enhanced Astrocytic Ca\u3csup\u3e2+\u3c/sup\u3e Signals Contribute to Neuronal Excitotoxicity after Status Epilepticus
Status epilepticus (SE), an unremitting seizure, is known to cause a variety of traumatic responses including delayed neuronal death and later cognitive decline. Although excitotoxicity has been implicated in this delayed process, the cellular mechanisms are unclear. Because our previous brain slice studies have shown that chemically induced epileptiform activity can lead to elevated astrocytic Ca2+ signaling and because these signals are able to induce the release of the excitotoxic transmitter glutamate from these glia, we asked whether astrocytes are activated during status epilepticus and whether they contribute to delayed neuronal death in vivo. Using two-photon microscopy in vivo, we show that status epilepticus enhances astrocytic Ca2+ signals for 3 d and that the period of elevated glial Ca2+ signaling is correlated with the period of delayed neuronal death. To ask whether astrocytes contribute to delayed neuronal death, we first administered antagonists which inhibit gliotransmission: MPEP [2-methyl-6-(phenylethynyl)pyridine], a metabotropic glutamate receptor 5 antagonist that blocks astrocytic Ca2+ signals in vivo, and ifenprodil, an NMDA receptor antagonist that reduces the actions of glial-derived glutamate. Administration of these antagonists after SE provided significant neuronal protection raising the potential for a glial contribution to neuronal death. To test this glial hypothesis directly, we loaded Ca2+ chelators selectively into astrocytes after status epilepticus.We demonstrate that the selective attenuation of glial Ca2+ signals leads to neuronal protection. These observations support neurotoxic roles for astrocytic gliotransmission in pathological conditions and identify this process as a novel therapeutic target
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