Disentangling the determinants of symbiotic species richness in native and invasive gammarids (Crustacea, Amphipoda) of the Baltic region

Dispersal of alien species is a global problem threatening native biodiversity. Co-introduction of nonnative parasites and pathogens adds to the severity of this threat, but this indirect impact has received less attention. To shed light on the key factors determining the richness of microorganisms in native and invasive host species, we compared symbiotic (parasitic and epibiotic) communities of gammarids across different habitats and localities along the Baltic coast of Poland. Seven gammarid species, two native and five invasive, were sampled from 16 freshwater and brackish localities. Sixty symbiotic species of microorganisms of nine phyla were identified. This taxonomically diverse species assemblage of symbionts allowed us to assess the effect of host translocation and regional ecological determinants driving assembly richness in the gammarid hosts. Our results revealed that (i) the current assemblages of symbionts of gammarid hosts in the Baltic region are formed by native and co-introduced species; (ii) species richness of the symbiotic community was higher in the native Gammarus pulex than in the invasive hosts, probably reflecting a process of species loss by invasive gammarids in the new area and the distinct habitat conditions occupied by G. pulex and invasive hosts; (iii) both host species and locality were key drivers shaping assembly composition of symbionts, whereas habitat condition (freshwater versus brackish) was a stronger determinant of communities than geographic distance; (iv) the dispersion patterns of the individual species richness of symbiotic communities were best described by Poisson distributions; in the case of an invasive host, the dispersion of the rich species diversity may switch to a right-skewed negative binomial distribution, suggesting a host-mediated regulation process. We believe this is the first analysis of the symbiotic species richness in native and invasive gammarid hosts in European waters based on original field data and a broad range of taxonomic groups including Microsporidia, Choanozoa, Ciliophora, Apicomplexa, Platyhelminthes, Nematoda, Nematomorha, Acanthocephala and Rotifera, to document the patterns of species composition and distributio

Hybrid brain-computer interface and functional electrical stimulation for sensorimotor training in participants with tetraplegia: a proof-of-concept study

Background and Purpose: Impaired hand function decreases quality of life in persons with tetraplegia. We tested functional electrical stimulation (FES) controlled by a hybrid brain-computer interface (BCI) for improving hand function in participants with tetraplegia. Methods: Two participants with subacute tetraplegia (participant 1: C5 Brown-Sequard syndrome, participant 2: complete C5 lesion) took part in this proof-of-concept study. The goal was to determine whether the BCI system could drive the FES device by accurately classifying participants' intent (open or close the hand). Participants 1 and 2 received 10 sessions and 4 sessions of BCI-FES, respectively. A novel time-switch BCI strategy based on motor imagery was used to activate the FES. In one session, we tested a hybrid BCI-FES based on 2 spontaneously generated brain rhythms: a sensory-motor rhythm during motor imagery to activate a stimulator and occipital alpha rhythms to deactivate the stimulator. Participants received BCI-FES therapy 2 to 3 times a week in addition to conventional therapy. Imagery ability and muscle strength were measured before and after treatment. Results: Visual feedback was associated with a 4-fold increase of brain response during motor imagery in both participants. For participant 1, classification accuracy (open/closed) for motor imagery-based BCI was 83.5% (left hand) and 83.8% (right hand); participant 2 had a classification accuracy of 83.8% for the right hand. Participant 1 had moderate improvement in muscle strength, while there was no change for participant 2. Discussion and Conclusion: We demonstrated feasibility of BCI-FES, using 2 naturally generated brain rhythms. Studies on a larger number of participants are needed to separate the effects of BCI training from effects of conventional therapy

Reach and grasp by people with tetraplegia using a neurally controlled robotic arm

Paralysis following spinal cord injury (SCI), brainstem stroke, amyotrophic lateral sclerosis (ALS) and other disorders can disconnect the brain from the body, eliminating the ability to carry out volitional movements. A neural interface system (NIS)1–5 could restore mobility and independence for people with paralysis by translating neuronal activity directly into control signals for assistive devices. We have previously shown that people with longstanding tetraplegia can use an NIS to move and click a computer cursor and to control physical devices6–8. Able-bodied monkeys have used an NIS to control a robotic arm9, but it is unknown whether people with profound upper extremity paralysis or limb loss could use cortical neuronal ensemble signals to direct useful arm actions. Here, we demonstrate the ability of two people with long-standing tetraplegia to use NIS-based control of a robotic arm to perform three-dimensional reach and grasp movements. Participants controlled the arm over a broad space without explicit training, using signals decoded from a small, local population of motor cortex (MI) neurons recorded from a 96-channel microelectrode array. One of the study participants, implanted with the sensor five years earlier, also used a robotic arm to drink coffee from a bottle. While robotic reach and grasp actions were not as fast or accurate as those of an able-bodied person, our results demonstrate the feasibility for people with tetraplegia, years after CNS injury, to recreate useful multidimensional control of complex devices directly from a small sample of neural signals

Volitional modulation of optically recorded calcium signals during neuroprosthetic learning

Brain-machine interfaces are not only promising for neurological applications, but also powerful for investigating neuronal ensemble dynamics during learning. We trained mice to operantly control an auditory cursor using spike-related calcium signals recorded with 2-photon imaging in motor and somatosensory cortex. Mice rapidly learned to modulate activity in layer 2/3 neurons, evident both across- and within-sessions. Learning was accompanied by striking modifications of firing correlations within spatially localized networks at fine scales

Sezonowe zmiany stężenia składników biogenicznych dwóch płytkich jezior przymorskich Gardna i Łebska; Porównanie

The aim of this paper was the presentation and comparison of seasonal biogens changes and trophy state classification of two biggest shallow coastal lakes Gardno and Łebsko, located in the northern part of Poland, along the southern coast of the Baltic Sea. Measurements were conducted once a month from April to December 2007. For the purpose of this article at each lake one measurement station was selected, to represent well mixed area of the lakes, far from outlet to the sea and rivers. Performed measurements showed that the lakes are similar. The differences, observed between biogens concentration in lakes were statistically insignificant. Seasonal dynamics of nutrients concentration in lakes indicated that the lakes are typical shallow lakes. Moreover, the summer concentration of total nitrogen and phosphorus qualify these lakes as eutrophic.Celem niniejszego opracowania była prezentacja i porównanie sezonowych zmian stężenia substancji biogenicznych oraz określenie poziomu trofii dwóch jezior przymorskich Gardna i Łebska. Jeziora te zlokalizowane są wzdłuż południowego wybrzeża Morza Bałtyckiego. Zaprezentowane rezultaty są wynikiem badań prowadzonych od kwietnia do grudnia 2007 roku. Do celów publikacji na każdym z jezior wyselekcjonowane zostało jedno stanowisko pomiarowe, charakteryzujące się zarówno minimalnym oddziaływaniem słonych wód morskich, jak i słodkich wód rzecznych. Przeprowadzone analizy wykazały, iż dynamika składników biogenicznych w omawianych jeziorach jest podobna, a różnice stężenia poszczególnych form azotu i fosforu nie są istotne statystycznie. Ponadto zaobserwowano, że sezonowe zmiany stężenia biogenów w Gardnie i Łebsku mają przebieg typowy dla jezior płytkich. Określenie poziomu trofii jezior opierało się na porównaniu letnich stężeń azotu i fosforu całkowitego w toni wodnej jezior. Na podstawie tych porównań zarówno Łebsko, jak i Gardno zakwalifikowano do typu eutroficznego

Precipitation as a nutrient source - on the example of Dobra Lake (northern Poland)

Badania pionowej dostawy substancji biogenicznych oraz określenia roli opadu atmosferycznego w kształtowaniu trofii jeziora Dobra przeprowadzone były w 2008 roku. Pomiary obejmowały oznaczenie wielkości opadu atmosferycznego, jego pH i przewodnictwo oraz ładunek substancji mineralnych (N-NO3, N-NH4 i P-PO4). Obliczono również zawartość substancji biogenicznych w toni wodnej jeziora. Określono, że w ciągu roku bezpośrednio do jeziora Dobra, na skutek opadu atmosferycznego wprowadzone zostało 238ź103m3 wody, co stanowi około 18% całkowitej jego objętości. Wraz z opadem do jeziora w ciągu całego roku dostarczone zostało odpowiednio 74,3 kg N-NO3, 82,1 kgN-NH4 i 9,8 kg P-PO4. W przeliczeniu na hektar powierzchni daje to ładunek rzędu 5,5kgN i 0,35kgP. Obliczono, że taka pionowa dostawa nutrientów stanowi około 30% zasobów całego zbiornika (32% N i 26% P). Ponadto ustalono, że roczna dostawa atmosferyczna jedynie mineralnych form azotu jak i fosforu do jeziora stanowi już około 50% ich dopuszczalnego ładunku Tym samym sądzić można, że ten sposób pionowej obszarowej dostawy biogenów jest istotnym elementem wpływającym na jakość wód i produktywność jeziora Dobra.Studies of the vertical nutrients deposition and the role of precipitation in Dobra Lake productivity were carried out in 2008. Measurements included determination of precipitation volume, pH, conductivity and mineral nutrients forms (N-NO3, N-NH4, P-PO4). Moreover nutrients content in whole lake was calculated. It was determined that in 2008 directly into the lake with precipitation was introduced 238ź103m3 of water, which is about 18% of its total volume. Annual amount of nutrients brought along with precipitation was 74.3 kg N-NO3, 82.1 kgN-NH4 and 9.8 kg P-PO4. It is about 5.5kgN and 0.35kgP per one hectare. It was calculated that such vertical nutrient supply constitute about 30% of all lake resources (32% N and 26% P). Moreover, it was determined, that atmospheric inputs represent highly significant loadings (about 50%) when compared with permissible nutrients loading. Therefore, it can be expected, that rainfall deposition is an important factor which influences on Dobra Lake trophy level

Impact of EU funds on rural areas development

W opracowaniu przedstawiono sposoby wykorzystania funduszy unijnych przez dwie gminy z województwa pomorskiego. Pozyskane środki umożliwiły poprawę jakości dróg, rozbudowę parkingów, budowę boisk i ośrodków kultury. Wyniki badań wskazują, iż korzystanie z dotacji zależało od wielkości gminy oraz przedsiębiorczości i pomysłowości lokalnych władz samorządowych.The paper presents ways how the EU funds were use by the two rural communities in Pomerania province. Acquired funds enabled the improvment of the quality of roads, expansion of parking lots, building playgrounds and cultural centres. The results of research indicate that the use of the support depended on the size of community and local authorities’ enterpreneurship and ingenuity