Wide Central Area Research Articles

Pond basin colonization by terrestrial vegetation indicates wetland deterioration

Abstract Efforts to conserve the pond network in the Doñana National Park are being threatened by groundwater overexploitation. The dramatic expansion of farming and tourism in nearby areas has caused a severe lowering of the water table, reducing pond hydroperiod length or even instigating pond desiccation. It is important to document the link between groundwater abstraction and pond deterioration with a view to decreasing human pressures on the park and preserving the pond network's singular biodiversity. Here, the gradual deterioration of one of the network's main ponds is described in detail by characterizing vegetation patterns within the pond's basin using orthophotos taken between 1956 and 2019. In the earliest images, the pond contained a wide central area of bare soil during its dry phase. This area was surrounded by reeds and had a line of Tamarix canariensis trees along its southern edge. Starting in 2000, the orthophotos showed the pond's gradual colonization by terrestrial vegetation. In tandem, pond hydroperiod decreased, as did the length of time the pond retained certain depths of water. In recent years, Tamarix trees finally fully invaded the pond's central area, which is surrounded by reeds and has scattered terrestrial bushes and pines. This invasion resulted from the pond's sparse inundation over recent decades, being the cover of trees related to the depth of groundwater, and is a clear sign of pond deterioration. More broadly, colonization by terrestrial vegetation has been observed in approximately 60% of the network's ponds. Colonization of temporary pond basins by terrestrial vegetation can be used as an indicator of deterioration and highlights the need for active restoration and management.

Aristotle’s Mixture in its Medical and Philosophical Background: The Hippocratic De victu and the Aristotelian De generatione et corruptione

Aristotle’s notion of qualitative interaction ruling both the process of mixture and the process of reciprocal elemental transmutation is based upon the idea of a physical contrariety endowed with two extremes and a wide central area where the opposite forces reach different equilibrium points (i.e., the so-called mixtures) or can be present to the fullest degree (in this case we do not have a mixture, but an element). Differently from previous scholarship which attributes this notion specifically to Aristotle, we have found, in a text which Aristotle seems to have been acquainted with, the Hippocratic De victu, an incipient structure of a contrariety endowed with extremes and a central area where opposite forces meet and yield respective equilibrium points, mixtures, which, as in Aristotle, give an account of the variety of beings existing in the world. In this article, we suggest the possibility that in the development of the Aristotelian thinking about elemental and qualitative dynamics, the Hippocratic De victu may have contributed to suggesting to Aristotle a way of envisioning the structure of his basic physical contrarieties.

<p><strong><em>Kurtkrammeria tiancaiensis</em></strong><strong> sp. nov. a new cymbelloid species (Bacillariophyceae) from Lijiang Laojunshan National Park in Yunnan Province, China</strong></p>

During a survey of freshwater diatoms from a mountain lake, Lake Tiancai, Laojunshan National Park, Hengduan Mountain Range, Lijiang City, Yunnan Province, China, a new Kurtkrammeria species, Kurtkrammeria tiancaiensis sp. nov. was recorded. A detailed morphological description of K. tiancaiensis is presented, based on light and scanning electron microscopy. The main features of K. tiancaiensis include slightly dorsiventral valves with narrowly rounded, or slightly protracted ends, a wide central area, apical pore fields at both poles and lack of stigmata. The new species is compared with K. treinishii, K. weilandii, K. lacusglacialis and K. eileencoxiae (≡ Gomphonema eileencoxiae), all of which show similar valve outlines to K. tiancaiensis, but differ in details of size, striae density, puncta density, number of apical pore fields, shape of the central area and/or presence of stigmata.

The spatial reliability of task-irrelevant sounds modulates bimodal audiovisual integration: An event-related potential study

The integration of multiple sensory inputs is essential for perception of the external world. The spatial factor is a fundamental property of multisensory audiovisual integration. Previous studies of the spatial constraints on bimodal audiovisual integration have mainly focused on the spatial congruity of audiovisual information. However, the effect of spatial reliability within audiovisual information on bimodal audiovisual integration remains unclear. In this study, we used event-related potentials (ERPs) to examine the effect of spatial reliability of task-irrelevant sounds on audiovisual integration. Three relevant ERP components emerged: the first at 140–200ms over a wide central area, the second at 280–320ms over the fronto-central area, and a third at 380–440ms over the parieto-occipital area. Our results demonstrate that ERP amplitudes elicited by audiovisual stimuli with reliable spatial relationships are larger than those elicited by stimuli with inconsistent spatial relationships. In addition, we hypothesized that spatial reliability within an audiovisual stimulus enhances feedback projections to the primary visual cortex from multisensory integration regions. Overall, our findings suggest that the spatial linking of visual and auditory information depends on spatial reliability within an audiovisual stimulus and occurs at a relatively late stage of processing.

Taxonomic revision of Chamaepinnularia krookiformis Lange-Bertalot et Krammer with a description of Chamaepinnularia plinskii sp. nov.

The benthic diatoms collected during our recent research in athalassic habitats exemplify a high morphological variability within Chamaepinnularia krookiformis Lange-Bertalot et Krammer. The species has already been known from freshwater ecosystems as well as from brackish waters in different regions of Europe. This variability has been also confirmed by the analysis of the literature. However, this is the first time that the morphological variability of the species has been addressed. In order to revise C. krookiformis and describe a new species, which has been distinguished on the basis of our material, we compared it with the type material of Pinnularia krookiformis Krammer 1992 from the periodic saline pool in Nordrhein-Westfalen (Germany). This study deals with a morphological analysis based on a large populations of C. krookiformis from Pelczyska (Central Poland). Selected morphological features were analysed, i.e.: valve length and width, number of striae in 10 µm, apices width, constrictions width, apices/constrictions width ratio, central-area length, and valve/central area length ratio. The results of light (LM) and scanning (SEM) microscopy, supported by multidimensional scaling (MDS), allowed for the distinction of three different morphotypes. Two of them match Krammer concept of Pinnularia krookiformis from 1992, while the third, occurring in our samples in three sampling sites, is clearly different. Thus, we described a new species Chamaepinnularia plinskii sp. nov., by the following major features: the valves are linear, symmetric, with rounded, capitate apices, the axial area is narrow, expanding to a wide central area forming a fascia, distal raphe endings are hooked to the same side of the valve and striae slightly radiate in the middle and in the rounded apices, becoming parallel in constrictions, 20-26 in 10 µm. This species occurs in inland waters with a wide range of chloride concentration, from 1000 to 3500 mg.l-1.

Influence of bottom currents on the sedimentary processes at the western tip of the Gulf of Corinth, Greece

We investigated the sedimentary processes that were active during the Holocene in the Gulf of Corinth, using high-resolution seismic reflection profiles and gravity cores. Seismic reflection data clearly show the presence of shallow-water sediment drifts at the western end of the Gulf, close to the Rion sill that links the Gulf to the Ionian Sea. Short cores indicate that drifts are composed of homogenous bioturbated mud in their upper part. The drift deposits flank a wide central area where the seafloor is eroded and where pre-Holocene deposits locally outcrop. The seafloor morphology in this area is marked by furrows oriented in different directions and by a depression attributed to the action of bottom-currents. The magnetic fabric of sediment samples from the drift, shelves, sub-basins and from the basin floor shows a significant anisotropy and a similar orientation of Kmax axes along core. The largest anisotropy (P=1.043±0.007) is observed in the drift and is interpreted as resulting from the action of bottom currents. The similar orientation of Kmax axes in the other cores, collected from areas east of the drifts, suggests that bottom currents also affect sediment deposition in the rest of the study area, even if seismic profiles and core analyses demonstrate that gravitational processes such as submarine landslides and turbidity currents exert the main control on sediment transport and deposition. Average Kmax axes for four cores were reoriented using the declination of the characteristic remanent magnetization. Kmax axes show variable orientations relatively to the slope of the seafloor, between along-slope and roughly parallel to the contour lines.

The temporal reliability of sound modulates visual detection: An event-related potential study

Utilizing the high temporal resolution of event-related potentials (ERPs), we examined the effects of temporal reliability of sounds on visual detection. Significantly faster reaction times to visual target stimuli were observed when reliable temporal information was provided by a task-irrelevant auditory stimulus. Three main ERP components related to the effects of auditory temporal reliability were found: the first at 180–240ms over a wide central area, the second at 300–400ms over an anterior area, and the third at 300–380ms over bilateral temporal areas. Our results support the hypothesis that temporal reliability affects visual detection and indicate that auditory facilitation of visual detection is partly due to spread of attention and thus results from implicit temporal linking of auditory and visual information at a relatively late processing stage.

Contrast-enhanced ultrasound appearance of primary epiploic appendagitis

Primary epiploic appendagitis (PEA) is a rare, benign self-limiting condition more often secondary to torsion or spontaneous venous thrombosis of a draining vein of the epiploic appendages; symptoms can mimic an acute abdomen [1]. The diagnosis is based on abdominal computed tomography or ultrasound [2–5]. More recently, a fairly characteristic contrast-enhanced ultrasound (CEUS) feature was described as a central area of no enhancement [6]. A 38-year-old man with a body mass index of 27 and without any significant clinical history was admitted to our hospital for the abrupt onset of acute localised pain in the left lower quadrant of the abdomen. The patient was afebrile and had no intestinal symptoms. The blood tests showed no abnormalities. Grey-scale ultrasound examination focused on the point of maximal tenderness revealed a well-delineated, oval, and homogeneously hyperechoic intra-abdominal mass, with a maximum diameter of 30 mm. The mass was adjacent to the abdominal wall and located anteromedial and adherent to the left colon. It was uncompressible and no thickening of the left colon wall was identified (Fig. 1). Fig. 1 Grey-scale ultrasound focused on the point of maximal tenderness. An oval hyperechoic mass is adherent to the left colon wall (arrow). Arrowheads mark the boundary of the mass The mass was evaluated with CEUS: a blood pool second-generation contrast agent (SonoVue®, Bracco, Milan, Italy) and a Philips iU22 ultrasound machine (Philips Healthcare, Best, The Netherlands) with a contrast harmonic imaging technology and a 3–9 MHz linear probe were used. The real-time images were displayed on a split screen: the left side displayed the contrast harmonic imaging, allowing the visualisation of the microvascularisation without the fundamental grey-scale echoes; the right side of the screen displayed the grey-scale images. The contrast harmonic imaging revealed a thick rim of arterial enhancement and a wide hypoechoic central area (Fig. 2). The CEUS appearance of the mass was unvaried in the venous phase; in particular, the wide central area remained hypoechoic. A computed tomography scan revealed the typical features of PEA (Fig. 3) [7]. Fig. 2 Contrast-enhanced ultrasound (arterial phase). The left image shows a thick rim of enhancement and a hypoechoic central area of the mass. On the right side is displayed the grey-scale image. Arrowheads mark the boundary of the mass Fig. 3 Computed tomography. An oval lesion (arrow), 2 cm in diameter, with attenuation similar to that of fat and with surrounding inflammatory changes, is localised next to the anterior left colon wall The patient was managed conservatively and the symptoms were completely resolved after 6 days. The follow-up grey-scale ultrasound, 4 and 19 days from the first examination, revealed progressive shrinkage of the mass. The patient gave informed written consent for the grey-scale sonography, the CEUS, and the computed tomography. Specific clinical features and grey-scale sonography findings of PEA are lacking; furthermore, there is the absence of flow in colour Doppler imaging [8, 9]. In this single patient, CEUS has confirmed that a thick rim of enhancement and a hypoechoic central area of the mass are characteristic features of PEA, as was previously reported by Gorg [6]. Therefore, in the adequate clinical context, the use of CEUS can give an immediate answer, thus allowing the diagnosis of PEA at the bedside.

Origin and evolution of Western European moles (genus Talpa, Insectivora): a multidisciplinary approach

ABSTRACT The European representatives of the subfamily Talpinae belong to the monophyletic genus Talpa. Five out of the nine species of Talpa occur in Western Europe. A wide central area is occupied by Talpa europaea, while the small sized Talpa caeca occurs in southern Europe. Three endemic species are restricted to the peripheral areas of the genus range and show a parapatric distribution with respect to T. europaea, i.e. the Iberian T. occidentalis, the southern Italian T. romana and the Balkan T. stankovici. The karyotypes of moles are very conservative, with the majority of the species showing 2n = 34. Allozyme data first allowed to assess the specific status of endemic taxa and the low levels of heterozygosity. Nei's genetic distances suggest that T. occidentalis, T. romana and T. stankovici early diverged from an europaea–caeca line. Preliminary results from mtDNA analyses strongly support the monophyly of Western European moles, but are still not able to solve the relationships within this clade. ...

Changes in retinal projections and ganglion cell morphology after unilateral enucleation in the common carp.

Changes in retinal projections and ganglion cell morphology were studied in one-eyed individuals of the common carp, Cyprinus carpio, which were enucleated at a juvenile stage (within 6 months after hatching) and kept for 18 months after the operation. Gross examination of the brains showed a marked atrophy of the contralateral optic tectum and a fine attenuated optic tract ipsilateral to the remaining eye. All retinal recipient areas were bilateral, but numerous projections were heavier contralaterally. Terminal branches in the recipient areas showed more complex patterns with tortuous courses and larger numbers of terminal swellings than in normal animals. Total numbers and distribution patterns of ganglion cells in Nissl-stained retinal whole mounts of one-eyed carp were compared with those in normal carp. The total number of ganglion cells was estimated to be 14 x 10(4)-18 x 10(4) in both one-eyed and normal carp. No difference was observed in isodensity maps and soma area histograms between one-eyed and normal carp. Following injections of horseradish peroxidase and nuclear yellow into the optic tectum of each side, three different types of tectal projecting ganglion cells were observed in the remaining retina: contralaterally projecting (CP) cells, ipsilaterally projecting (IP) cells, and bilaterally projecting (BP) cells. The distribution pattern of CP and BP cells in the retina suggested normal retinotopy. However, BP cells were found in a more restricted zone within the CP cell distribution area. The IP cells had a tendency to be scattered sparsely in a wide central area and a dorsal quadrant of the retina. No IP or BP cells were found in the peripheral retina. The time course and morphological changes in axons of these cells are discussed.

Population changes in Egypt and Nubia

There appears to have existed a basic population type stretching over the wide centralarea limited to the North (Middle Egypt) by a morphological type with a broad skull and to the South by the Nubian groups having negroid traits. The history of the population changes in Egypt and Nubia up to the Roman period can be explained as a result of infiltrations in both directions of these two marginal groups, varying in direction throughout the period.

Der skal ikke lades sten på sten tilbage

Der skal ikke lades sten på sten tilbage