Building on the Promise: State Initiatives to Expand Access to Early Head Start for Young Children and Their Families

Discusses twenty states' approaches to expanding and enhancing Early Head Start services, opportunities and challenges for state initiatives, and recommendations for building on existing services for at-risk children. Calls for increased federal funding

Real-time tracking of electrode during deep-brain surgery

LAUREA MAGISTRALEIl sistema sviluppato per questa tesi è parte di un progetto di ricerca che mira a definire e caratterizzare un nuovo modello di ictus subcorticale relativo al cervello nei primati. In particolare è stato deciso di riprodurre l’ictus subcorticale, usando un elettrodo termocoagulatore per generare una lesione del braccio posteriore della capsula interna. Prima della chirurgia, viene ideato un piano chirurgico per valutare come l’elettrodo debba essere introdotto all’interno del cervello, in modo da raggiungere correttamente la parte desiderata. Il piano chirurgico è basato su un Imaging a Risonanza Magnetica strutturale (MRI) acquisito prima della chirurgia, avendo come referenza un casco stereotassico nel quale è fissata la testa del primate. Tuttavia, nonostante questo, il chirurgo non può vedere la posizione dell’elettrodo all’interno del cervello durante l’intervento. Il sistema sviluppato in questa tesi ha l’obiettivo di aiutare il chirurgo, confermando in tempo reale la traiettoria dell’elettrodo all’interno del cervello. Per fare questo, è stato usato un dispositivo di tracciamento ottico, il Vicon Motion Capture System, per ottenere in tempo reale la posizione 3D dell’elettrodo tracciando la sua punta metallica. La stima della posizione dell’elettrodo è inviata al software 3D Slicer, che è usualmente usato per visualizzare la parte interna del cervello durante gli interventi chirurgici, attraverso la risonanza magnetica del primate. Il sistema è stato provato in una serie di interventi chirurgici simulati e, grazie alle informazioni ottenute dal sistema sviluppato, la capsula interna è stata raggiunta ogni volta con precisione millimetrica. Il sistema ha mostrato di avere una latenza complessiva nell’ordine dei 15 ms, che non creano problema alcuno al chirurgo durante l’intervento.The system developed in this thesis is part of a research project that aims to define and characterize a new model of subcortical stroke relative to primate brain. In particular it has been decided to reproduce a subcortical stroke, by using a thermocoagulation electrode to generate a lesion of the posterior limb of the internal capsule. Before the surgery, a surgical plan is used to evaluate how the electrode must be introduced in the brain to reach the desired brain part. The surgical plan is based on a structural Magnetic Resonance Imaging (MRI) acquired before the surgery, having as reference a stereotactic frame in which the monkey’s head is fixed. The stereotactic frame is a neuronavigation guidance that helps the surgeon during the surgery giving him a reference. However, despite this, the surgeon is completely blind during the surgery. The system developed in thesis aims to help the surgeon confirming in real-time the trajectory of the electrode inside the brain. To do that, an optical tracker device, the Vicon Motion Capture System, has been used to obtain, in real time, the 3D position of the electrode. In particular the Vicon System tracks the metallic stick that has on one end the electrode. The estimated electrode position is sent to the 3D Slicer software, which is usually used to visualize the inner part of the brain during the surgical intervention by means of the available primate’s MRI. The system has been tested in a series of simulated surgery interventions and, thanks to the information provided by the developed system, the internal capsule has been every time reached with a significant precision. The system has shown to have an overall latency in the order of 15 ms that does not create problems to the surgeon during the intervention

Culture of Channel Catfish in East-Central South Dakota Dugout Ponds

Twenty dugout ponds in east-central South Dakota were stocked 10 May 1980 with fingerling (mean weight 39.4 g, mean total length 108.4 mm) channel catfish (Ictalurus punctatus) at stocking rates of 309, 618, 1,235, and 1,853 fish/ha. Supplemental food was provided in 16 ponds (four at each stocking rate) at a rate of 4% body weight every other day. Fish in four ponds stocked, one at each of the respective stocking rates were not fed. Eleven of the 16 ponds which received feed were considered fit for analysis at the end of the study period, 27 September 1980. Two of the four ponds which did not receive feed were fit for analysis. Least square means were computed for fish lengths and weights. Final length least square means for the respective stocking rates in ponds receiving food were 274.2, 266.1, 260.6, and 231.2 mm. Final weight least square means for the respective stocking rates were 193.8, 163.3, 166.1, and 105.2 g. Tukey\u27s test revealed no significant (P \u3c 0.05) differences between the least square mean values for the 1,235/ha rate and the highest respective least mean square values for length, weight, or K(TL). For production purposes, the 1,235/ha stocking rate was determined to be the best of the four rates, yielding 107 kg/ha, and producing an average of 0.84 kg/ha/day. These growth and production values were less than those of similar studies conducted at more southerly latitudes and were determined to be unprofitable from an aquacultural view. The short growing season and less than optimum water chemistry conditions were believed to have hindered growth. Food habit analysis indicated the catfish were not markedly utilizing the stocked forage base of fathead minnows (Pimephales promelas). Taste evaluations by participating pond owners and a taste panel yielded favorable results. In the pond owner test, 93.3% of the respondents rated the flavor as acceptable. The taste panel rated 64% of the fish sampled as good to excellent in taste. Dugout ponds receiving little or no cattle usage were likely to have excess aquatic macrophytes, a probable result of greater water transparency. Assuming 100% collection efficiency, 65.2% of the 489 fish stocked in the 11 usable fed ponds survived. Dugout ponds are capable of supporting channel catfish and also have recreational fisheries potential. These ponds may have commercial potential with channel catfish if a different stocking strategy is followed. The dugout pond may also represent a bait fishery potential with fathead minnows. Future stockings of channel catfish in similar ponds might reach harvestable size if stocked at a larger size (203 - 254 mm total length). Assuming 100% recovery efficiency, 45 of 62 (72.6%) fish left to overwinter in three dugout ponds survived. A new dugout pond was found to be significantly (P≤ 0.01) less productive than an older pond. The mean annual zooplankton biomass for the newer pond was 121.6 mg/l while that of the older pond was 245.3 mg/l, both values were representative of eutrophic waters

Direct Palladium-Catalysed Cross-Coupling Reactions Between Organolithium or Organozinc Reagents and (Hetero)Aryl Bromides in Nonconventional Solvents

In spite of their enormous synthetic relevance, the use of highly polar organometallic reagents has been to date restricted to anhydrous conditions, inert atmosphere and low temperatures to avoid their fast decomposition and to control their reactivity. One of the most momentous challenge in organic synthesis is the replacement of harsh and volatile organic compounds by more environmentally responsible solvents.[1] Building upon our recent findings on the use of organometallics of in unconventional reaction media [e.g., the so-called deep eutectic solvents (DESs), water],[25] in this Communication we report that a wide range of alkyl- and aryllithium or organozinc reagents can undergo fast chemo- and regioselective cross-coupling reactions with (hetero)aryl bromides in the presence of a Pd catalyst, under mild reaction conditions and under air, using bulk water or DES as a privileged reaction medium, to afford the desired adducts in yields up to 98%.[6] The described protocols have been optimised so as to minimize the formation of byproducts mainly arising from a metal-halogen exchange and from a -hydride elimination reaction. This methodology opens up new vistas in the perspective of the development of a sustainable organometallic chemistry in bio-inspired solvents

SCALABLE PALLADIUM-CATALYSED NEGISHI CROSS-COUPLING REACTIONS BETWEEN ORGANOZINC REAGENTS AND (HETERO)ARYL BROMIDES IN NONCONVENTIONAL SOLVENTS

In spite of their enormous synthetic relevance, the use of polar organometallic reagents has been to date restricted to anhydrous conditions, inert atmospheres and low temperatures to avoid their fast decomposition and to control their reactivity. One of the most momentous challenge in organic synthesis is the replacement of harsh and volatile organic compounds by more environmentally responsible solvents.[1] Building upon our recent findings on the use of organometallics in unconventional reaction media [e.g., the so-called deep eutectic solvents (DESs), water],[2 7] in this Communication we report that a wide range of alkyl- and arylzinc reagents can undergo fast chemo- and regioselective cross-coupling reactions with functionalized (hetero)aryl bromides in the presence of a Pd catalyst, under mild reaction conditions and under air, using bulk water or DES as a privileged reaction medium, to afford the desired adducts in yields up to and over 98% (Figure 1).[8] The described protocol is scalable (up to 5g), and proceed in the absence of additional ligands, and with an easy recycling of both the DES or water and the catalyst. This methodology opens up new vistas in the perspective of the development of a sustainable organometallic chemistry in bio-inspired solvents

Pd-catalyzed Reductions in Deep Eutectic Solvents by Using Aluminum and Water as Hydrogen Source

The reduction of organic functional groups, using metal-catalyzed hydrogenations, is one of the most employed strategy in organic chemistry for the synthesis of both fine and bulk chemicals.[1] Hydrogen is an explosive gas and its production needs extensive energy and generates a considerable amount of carbon dioxide. Therefore, the development of cost-effective reduction methods that use safe reagents, environmentally-friendly solvents and prevent or minimize waste formation represents a challenge of great interest in sustainable chemistry. As part of our ongoing efforts in the discovery of sustainable synthetic methodologies,[2] an alternative and safe palladium-catalyzed hydrogenation reaction in Deep Eutectic Solvents (DESs) is here described.[3] The use of aluminum powder in combination with water and a base in DESs, results in an environmentally-responsible system for the controlled in-situ generation of hydrogen. Our optimized protocol is effective for the reduction of a wide range of functional groups, containing C–C, C–N, C–O, N–O multiple bonds as well as for the dearomatization of (hetero)aromatic compounds, and leads to the desired products in yield up-to 99%. The simplicity, cost, tunability, scalability and the environmentally benign character of both catalytic system and DESs, offer numerous advantages over the currently available methods that employ external and dangerous H2 source and harsh, volatile organic solvents

A route to benzodithiophene systems by exploiting a ligand-free Suzuki-Miyaura coupling reaction in deep eutectic solvents

Benzo[1,2-b:4,3-b\u2019]dithiophene (BDT) and its derivatives belong to an interesting class of thiophene-based aromatic \uf070-conjugated compounds that are widely studied as functional organic materials inserted, for instance, as units in mono and polydisperse oligomers [1], or as \uf070-spacers in push-pull organic chromophores for photovoltaic applications [2]. Moreover, BDTs are key intermediates for the synthesis of inherent chiral tetrathia[7]helicenes, which are an attractive class of heterohelicenes with unique physicochemical and chiroptical properties due to their helix-like structure [3]. Thus, BDT is a key starting molecule which can allow access to more complex and interesting systems through a selective and judicious functionalization of the \uf061 and \uf062-positions of the terminal thiophene rings. Building on our recent studies on the synthesis and functionalization of BDTs [4], we questioned whether a novel class of 2,7-diarylsubstituted BDTs 1 (Figure 1) could be synthesized via a palladium-catalysed Suzuki-Miyaura reaction between heteroaryl halides 2 and organoboron derivatives 3 in Deep Eutectic Solvents (DESs), which have proven to be effective as sustainable and environmentally responsible reaction media in several transition-metal-catalyzed reactions [5].In this communication, we report our preliminary results on the preparation of diarylsubstituted BDTs 1, and discuss the substrate scope of the proposed protocol. Some of the compounds so far obtained display interesting photophysical properties, which are currently under investigation