Age-related differences in pointing accuracy in familiar and unfamiliar environments

This study aimed to investigate age-related differences in spatial mental representations of familiar and unfamiliar places. Nineteen young adults (aged 18\u201323) and 19 older adults (aged 60\u201374), all living in the same Italian town, completed a set of visuospatial measures and then pointed in the direction of familiar landmarks in their town and in the direction of landmarks in an unknown environment studied on a map. Results showed that older adults were less accurate in the visuospatial tasks and in pointing at landmarks in an unfamiliar environment, but performed as well as the young adults when pointing to familiar places. Pointing performance correlated with visuospatial tests accuracy in both familiar and unfamiliar environments, while only pointing in an unknown environment correlated with visuospatial working memory (VSWM). The spatial representation of well-known places seems to be well preserved in older adults (just as well as in young adults), while it declines for unfamiliar environments. Spatial abilities sustain the mental representations of both familiar and unfamiliar environments, while the support of VSWM resources is only needed for the latter

Investigation into the voltammetric behaviour and detection of selenium(IV) at metal electrodes in diverse electrolyte media

The voltammetric behaviour of selenium(IV) was studied at platinum and gold electrodes in sulphuric acid, perchloric acid and potassium chloride media as a basis for its voltammetric detection. The best voltammetric behaviour was recorded at gold electrodes with perchloric acid as the supporting electrolyte. The concomitant presence of metals, such as copper or lead, and of model biomolecules, such as bovine serum albumin, in the solution resulted in a deterioration of the electrochemical response for selenium(IV). Quantitative detection of selenium(IV) by square wave anodic stripping voltammetry at both a millimetre-sized gold disc electrode and a microband electrode array revealed linear responses to selenium concentration in the ranges of 5-15 μM and 0.1-10 μM, respectively, with 60 s preconcentration. The sensitivities were 6.4 μA μM-1 cm-2 and 100 μA μM-1 cm-2 at the disc and the microband array, respectively. The detection limit at the microband electrode array was 25 nM, illustrating the potentiality of such microelectrodes for the development of mercury-free analytical methods for the trace detection of selenium(IV)

The ground state properties of the spin-1/2 transverse Ising chain with periodically varying bonds and fields

Using continued fractions we study the ground state properties of the spin-1/2 Ising chain in a transverse field with periodically varying interaction strengths and external fields. We consider in detail the chain having the period of modulation of interactions equals 2 and compare the results obtained with those corresponding to the spin-1/2 isotropic XY chain in a transverse field. In contrast to the behaviour of the transverse XY chain, the transverse Ising chain does not exhibit a step-like magnetization vs. field dependence caused by the alternation of bonds, its susceptibility exhibits a logarithmic singularity at the field determined by interaction strengths, and it is stable with respect to spin-Peierls dimerization.Comment: 11 pages, latex, 4 figure

Analisis Kompetensi Guru Sebagai Bagian Dari Pedagogical Content Knowledge Guru Dalam Menerapkan Pendekatan Saintifik Dalam Program Plpg

The purpose of this research is to analyze the competence of teachers as part of the teachers\u27 pedagogical content knowledge in applying scientific approach in Mathematics PLPG (in-service teacher education and professional training) program rayon 138 Yogyakarta, Indonesia, in 2014. The research method used is descriptive with quantitative approach. The subjects of the study consisted of 23 mathematics teachers including mathematics teachers of junior high school, high school and vocational school from Kebumen, Purworejo, and Magelang. Data was collected by filling in a questionnaire at the beginning and end of the training, observing microteaching activities, and documenting the learning material arranged by PLPG participants. Based on the analysis, it can be concluded that PLPG especially PLPG rayon 138 Yogyakarta, Indonesia, in 2014 gives benefits for the development of teachers\u27 PCK, especially in terms of teachers\u27 competence in applying scientific approach. Based on the analysis of learning materials arranged by the teachers and analysis of learning videos, it is known that the majority of the teachers have been able to construct a learning material using scientific approach and implement it properly

Evidence for age-related deficits in object-location binding during place recognition.

Deciding whether a place is the same or different than places encountered previously is a common task in daily navigation which requires to develop knowledge about the locations of objects (object-location binding) and to recognize places from different perspectives. These abilities rely on hippocampal functioning which is susceptible to increasing age. Thus, the question of the present study is how they both together impact on place recognition in aging. Forty people aged 20-29, 44 aged 60-69, and 32 aged 70-79 were presented with places consisting of four different objects during the encoding phase. In the test phase, they were then presented with a second place and had to decide whether it was the same or different. Test places were presented from different perspectives (0°, 30°, 60°) and with different object conditions (same, a swap of two objects, a substitution with a novel object). The sensitivity for detecting changes (d') decreased from 20-29 to 60-69 and to 70-79 years old, and with increasing perspective shifts. Importantly, older adults were less sensitive to object swapping than to object substitution, while young participants did not show any difference. Overall, these results suggest specific age-related difficulties in object-location binding in the context of place recognition

New multi-proxy record shows potential impacts of precipitation on the rise and ebb of Bronze Age and imperial Persian societies in southeastern Iran

The Achaemenids and Sasanian ‘Persian’ Empires were significant political, economic, and social forces in the Late Bronze Age and Late Antiquity Eurasia, respectively, which have left marks on the heritage of the Mediterranean and Middle Eastern world. While attention is often focused on military and political conditions when discussing the prosperity and decline of these imperial powers, their realms, which crossed a variety of environmental settings, were highly dependent on the predictability of rainfall that drove agriculture and effective provisioning. Here, we present a multi-proxy sedimentological, geochemical, and palynological record from a 2.5-m long peat deposit near the excavation site in Konar Sandal near Jiroft in southeastern Iran, covering 4000-850 cal yr BP. Around 3950 cal yr BP a wet period prevailed based on elemental ratios, stable C isotope, pollen, and diagnostic lipids. Between 3900 and 3300 cal yr BP, wet/semi-wet conditions developed with the appearance of Cerealia-type pollen. Dry and windy conditions followed (ca. 3300-2900 cal yr BP), which coincided with the Siberian anticyclones and climatic shifts developing in the Eastern Mediterranean region. Consequently, the Bronze Age settlements around Jiroft, dependent on agriculture, underwent a steady decline. A prolonged wet period followed (ca. 2900-2300 cal yr BP) with the abundance of Sparganium-type pollen and the aquatic lipid proxy (Paq). This change coincided with intensive agricultural practices and the flourishing of the powerful Median and Achaemenid empires. The shift to high Ti/Al ratios coeval with the lowest δ13COM values suggests an increase in aeolian activity and dry conditions ca. 2100-1650 cal yr BP. The Jiroft valley again experienced wet conditions between 1550 and 1300 cal yr BP, which overlapped with the economic prosperity of the middle to late Sasanian empire. The paleoenvironmental reconstruction indicates that wet periods and intensive agriculture coincide with the Persian empires' zenith, political influence, and economic affluence. Therefore, contextualized and detailed paleoenvironmental records are desirable to explore the interplay of political and climatic factors in the development and fragmentation of the ancient settlements and imperial powers in Eurasian history.1. Introduction 2. Geographical setting 3. Materials and methods 3.1. Sampling, magnetic susceptibility, and grain size analysis 3.2. Radiocarbon analyses 3.3. Elemental and mineralogical analyses 3.4. C/N and stable isotope analyses 3.4.1. Lipid extraction 3.5. Pollen analysis 4. Results 4.1. Age-depth model and chronology 4.2. Units 4.2.1. Unit 1 (U 1; 250-189 cm; ca. 4000-3550 cal yr BP) 4.2.2. Unit 2 (U 2; 189-164 cm; ca. 3550-3300 cal yr BP) 4.2.3. Unit 3 (U 3; 164-134 cm; ca. 3300-2900 cal yr BP) 4.2.4. Unit 4 (U 4; 134-106 cm; ca. 2900-2300 cal yr BP) 4.2.5. Unit 5 (U 5; 106-61 cm; ca. 2300-1550 cal yr BP) 4.2.6. Unit 6 (U 6; 61-10 cm; ca. 1550-850 cal yr BP) 5. Discussion 5.1. Paleoclimate preceding the decline of the Jiroft civilization 5.2. The Late Bronze Age decline in Jiroft 5.3. Rise and fall of the Persian Empire 5.3.1. The pre-Islamic period and recent times 6. Conclusion

Population dynamics of cobia Rachycentron canadum (Linnaeus, 1766) off Cochin coast, south-eastern Arabian Sea

Estimated landings of cobia from the Indian EEZ by the commercial fishing vessels are mostly as bycatch in hooks and line cum gillnet and trawl nets. However, the catches are substantial compared to that reported in several other countries of Asia. The species is also gaining considerable importance as a favoured candidate species for sea farming using cages. Very little is known about the fishery and biological characters such as maturation, fecundity and feeding preferences of cobia in Indian seas. Study indicated a fast growth rate with estimates of L∞ = 184 cm (FL) and K = 2.6 (yr-1) in cobia. The total mortality rate (Z) was estimated as 5.18, natural mortality (M) was 2.01 and fishing mortality (F) was 3.17 with an exploitation rate (E) of 0.61. The length at first capture (Lc50) estimated from the catch curve was 72 cm. Fecundity was found to be high and variable, with mean fecundity estimated as 12,37,545 eggs with a coefficient of variation (CV) of 16.7. As inferred from the oocyte development pattern, spawning activity is brief and fish is classified as synchronous ovulatory type. The growth parameters and condition factor estimated in this study indicate that relatively high growth rates are also possible in wild stocks considering that food is abundant and the environmental temperature is in the optimum range. Feeding preferences indicated balistid fish and shrimps with a wide variety of food items including finfishes, crustaceans and molluscs present

Spin-Peierls instability in a quantum spin chain with Dzyaloshinskii-Moriya interaction

We analysed the ground state energy of some dimerized spin-1/2 transverse XX and Heisenberg chains with Dzyaloshinskii-Moriya (DM) interaction to study the influence of the latter interaction on the spin-Peierls instability. We found that DM interaction may act either in favour of the dimerization or against it. The actual result depends on the dependence of DM interaction on the distortion amplitude in comparison with such dependence for the isotropic exchange interaction.Comment: 12 pages, latex, 3 figure

Heavy metals in coastal sediments of South Caspian Sea: natural or anthropogenic source?

This paper focuses on heavy metal distribution patterns in sediments of central Guilan (CG) and east Mazandaran (EM) in the south Caspian Sea coasts, north of Iran. Sediment sub-samples were retrieved from core and surficial samples in different environments of marine and coastal lagoons as well as coastal outcrops. Inductively Coupled Plasma Mass Spectrometry and Atomic Emission Spectrometry (ICP-MS and ICP-AES) analysis were used to determine the metal chemistry. Concentration of the selected heavy metals exhibited variations through sediment samples which are partially related to grain size and organic matter content. Geoaccumulation index and statistical procedures have been implemented for analyzing the absolute metal values. Result of the geoaccumulation index demonstrated that the metal distribution reflects the influence of geological background of the watershed area. Some elements including Pb, Ni, Cu, Sr and Ba showed elevated concentration in the CG that could be attributed to development of industrial activities. A comparison of the metal concentration in the marine sediments and the Late Holocene outcrops revealed that the level of the metals concentration at the sea generally corresponds to natural background. The northern part of Iranian multi-lithological catchments basin is the main source for the sediments that drained by the rivers to the South Caspian Sea basin

Fermented brewers’ spent grain containing dextran and oligosaccharides as ingredient for composite wheat bread and its impact on gut metabolome in vitro

Brewers’ spent grain or BSG is a fiber and protein rich food-grade side stream that has remained underutilized due to its poor technological and sensory characteristics. In this study, BSG was fermented with Weissella confusa A16 in presence of sucrose to induce the synthesis of dextran and maltosyl-isomaltooligosaccharides. Fermented BSG with or without the above polysaccharides was used as ingredient in wheat bread. Digestion of BSG breads was simulated in vitro with Simulator of Human Intestinal Microbial Ecosystem, and levels of fecal metabolites were analyzed. Enrichment of BSG breads with in situ dextran and maltosyl-isomaltooligosaccharides improved the baking quality compared to native BSG. Metabolism of free amino acids and synthesis of short chain fatty acids varied at different stages and parts of colon. The increase in butyric acid was similar in both the proximal and distal colon. In situ dextran and maltosyl-isomaltooligosaccharides, and higher content of proteins and fiber in BSG breads had a positive influence towards gut microbiota functionality. Along with several essential amino acids, an increase in amount of γ-aminobutyric acid was also observed after simulated digestion. BSG breads had a significant effect on the gut metabolome during in vitro digestion, showing increased production of microbial metabolites with potential health benefits