Effects of defruiting on source-sink relationship, carbon budget, leaf carbohydrate content and water use efficiency of apple trees

Three-year-old apple ( Malus domestica Borkh. cv. Golden Delicious) trees with ca 5 m² leaf area each were grown in situ in lysimeters and defruited either in August. September or October. Net photosynthesis, dark respiration and water use efficiency were measured for 5 days prior to and after fruit removal. using tree canopy chambers and infrared gas analysis with a dedicated interface and software. Net photosynthesis of the tree canopy declined after defruiting. irrespective of the month of defruiting. The decline after fruit removal was 30-40% in August or September and 57% in October. After defruiting in August or September, trees respired 50–60% slower in the dark, but 39% faster after defruiting in October. The excessive respiratory losses after fruit removal in October. when the tree lost more carbon than it assimilated. may have been induced by translocation of carbohydrates from the leaves to the perennial woody parts of the tree and by the onset of leaf senescence. Fruit removal in August or September increased water use efficiency by 31–41%. but decreased water use efficiency in October by 75%     

Reanalyzing the Palaeoptera problem – The origin of insect flight remains obscure

The phylogenetic relationships of the winged insect lineages – mayflies (Ephemeroptera), damselflies and dragonflies (Odonata), and all other winged insects (Neoptera) – are still controversial with three hypotheses supported by different datasets: Palaeoptera, Metapterygota and Chiastomyaria. Here, we reanalyze available phylogenomic data with a focus on detecting confounding and alternative signal. In this context, we provide a framework to quantitatively evaluate and assess incongruent molecular phylogenetic signal inherent in phylogenomic datasets. Despite overall support for the Palaeoptera hypothesis, we also found considerable signal for Chiastomyaria, which is not easily detectable by standardized tree inference approaches. Analyses of the accumulation of signal across gene partitions showed that signal accumulates gradually. However, even in case signal only slightly supported one over the other hypothesis, topologies inferred from large datasets switch from statistically strongly supported Palaeoptera to strongly supported Chiastomyaria. From a morphological point of view, Palaeoptera currently appears to be the best-supported hypothesis; however, recent analyses were restricted to head characters. Phylogenetic approaches covering all organ systems including analyses of potential functional or developmental convergence are still pending so that the Palaeoptera problem has to be considered an open question in insect systematics.     

Evaluating the forced oscillation technique in the detection of early smoking-induced respiratory changes

Background  

Early detection of the effects of smoking is of the utmost importance in the prevention of chronic obstructive pulmonary disease (COPD). The forced oscillation technique (FOT) is easy to perform since it requires only tidal breathing and offers a detailed approach to investigate the mechanical properties of the respiratory system. The FOT was recently suggested as an attractive alternative for diagnosing initial obstruction in COPD, which may be helpful in detecting COPD in its initial phases. Thus, the purpose of this study was twofold: (1) to evaluate the ability of FOT to detect early smoking-induced respiratory alterations; and (2) to compare the sensitivity of FOT with spirometry in a sample of low tobacco-dose subjects.     

Noncontact dipole effects on channel permeation. III. Anomalous proton conductance effects in gramicidin

Proton transport on water wires, of interest for many problems in membrane biology, is analyzed in side-chain analogs of gramicidin A channels. In symmetrical 0.1 N HCl solutions, fluorination of channel Trp(11), Trp-(13), or Trp(15) side chains is found to inhibit proton transport, and replacement of one or more Trps with Phe enhances proton transport, the opposite of the effects on K(+) transport in lecithin bilayers. The current-voltage relations are superlinear, indicating that some membrane field-dependent process is rate limiting. The interfacial dipole effects are usually assumed to affect the rate of cation translocation across the channel. For proton conductance, however, water reorientation after proton translocation is anticipated to be rate limiting. We propose that the findings reported here are most readily interpreted as the result of dipole-dipole interactions between channel waters and polar side chains or lipid headgroups. In particular, if reorientation of the water column begins with the water nearest the channel exit, this hypothesis explains the negative impact of fluorination and the positive impact of headgroup dipole on proton conductance.     

The head anatomy of Epiophlebia superstes (Odonata: Epiophlebiidae)

The relic dragonfly family Epiophlebiidae is recovered as sistergroup of Anisoptera (= Epiprocta) by most molecular and morphological analyses. However, in a recent study it was placed within Anisoptera as sister group of Cordulegastridae. In another study, several affinities to Zygoptera in the morphology of the ovipositor and the egg-laying behaviour were pointed out. Here, we present a detailed study of the outer, as well as the inner, head morphology of Epiophlebia superstes. Compared with the last detailed literature account, three additional mandibular muscles were discovered, as well as additional buccal and pharyngeal muscles. The results are compared with the anatomic features of Zygoptera and Anisoptera. A formal character evaluation focused on head characters confirms the sistergroup relationship of Epiophlebiidae and Anisoptera.     

Primary malignant melanoblastosis of the meninges. Clinical, cytologic and neuropathologic findings in a case

A 66-year-old man presented with a six-month history of neurologic symptoms suggestive of a craniospinal tumor or a diffuse inflammatory process in the subarachnoid space. Cytologic examination of cerebrospinal fluid (CSF) revealed inflammatory changes and malignant melanin-containing cells, leading to a diagnosis of meningeal spread of a melanoma. There was no history of skin excisions and no clinical evidence of primary melanoma of the eye. Neuroradiologic investigations, including CT and myelography, to confirm the diagnosis were negative. Despite intrathecal cytostatic therapy, the patient died eight months after the onset of symptoms. Autopsy disclosed diffuse meningeal melanoblastosis of the spinal cord and the base of the brain, confirming the cytologic diagnosis. In addition, two micrometastases in the liver were found as only extraneural manifestation. This case emphasizes the importance of CSF cytology in the diagnosis of diffuse infiltrating processes in the subarachnoid space.