Presidential Address ON MEDICAL EDUCATION IN RELATION TO OBSTETRICS.

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Reconciling the Differences Between the “Gender-Responsive” and the “What Works” Literatures to Improve Services for Girls

Recent increases in the delinquency and incarceration of girls have prompted juvenile justice professionals to search for effective, gender-specific prevention and treatment strategies. Given the dearth of research on girls\u27 programming, these professionals are often left to sort out discrepancies between two major bodies of literature that address the needs of delinquent girls—the “what works” literature and the “gender-responsive” literature. This article culls the best of what is available within both these bodies of literature and suggests programmatic elements deemed essential for working effectively with girls

Moving Ahead: Five Essential Elements for Working Effectively With Girls

Quite a bit of literature these days addresses what is believed to be an increase in the frequency and severity of girls\u27 problem behaviors and the need for gender-responsive treatment. The extent to which this literature has been translated into juvenile justice practices, however, appears limited by several factors. This article briefly discusses these impediments, and offers suggestions for five essential elements that reflect the current state of knowledge regarding effective intervention with girls involved in the juvenile justice system

Reconciling the Differences Between the “Gender-Responsive” and the “What Works” Literatures to Improve Services for Girls

Recent increases in the delinquency and incarceration of girls have prompted juvenile justice professionals to search for effective, gender-specific prevention and treatment strategies. Given the dearth of research on girls\u27 programming, these professionals are often left to sort out discrepancies between two major bodies of literature that address the needs of delinquent girls—the “what works” literature and the “gender-responsive” literature. This article culls the best of what is available within both these bodies of literature and suggests programmatic elements deemed essential for working effectively with girls

Moving Ahead: Five Essential Elements for Working Effectively With Girls

Quite a bit of literature these days addresses what is believed to be an increase in the frequency and severity of girls\u27 problem behaviors and the need for gender-responsive treatment. The extent to which this literature has been translated into juvenile justice practices, however, appears limited by several factors. This article briefly discusses these impediments, and offers suggestions for five essential elements that reflect the current state of knowledge regarding effective intervention with girls involved in the juvenile justice system

King Arthur of the Romans: Lucius Artorius Castus and the Sarmatians in Britain

U radu se iznose moguće veze između života rimskog vojnika iz 2. st., Lucija Artorija Kasta, i kasnijih, srednjovjekovnih legendi oko polumitskog kralja Artura. Autor pretpostavlja da se zahvaljujući natpisu otkrivenom u blizini Splita u Hrvatskoj (Podstrana), može izgraditi čvrsta teza da je Kast bio najstariji povijesni lik za koji se može dokazati da je utjecao na razvitak kasnijih legendi u Britaniji. Sačuvane su priče o sarmatskim ratnicima koji su u Britaniju došli kao dio rimskih legija, a kojima je zapovijedao sam Kast; naime sarmatske i keltske priče stapaju se međusobno u razdoblju nakon Kastovog života. Najstariji zapisi pokazuju da se potonji nije doživljavao kao kralj nego da je nosio naslov dux (zapovjednik) i da je bio karizmatični lider, a jedina osoba koja je nosila ime Artur bio je Lucije Artorije Kast. Ako je ispravna teorija o Artoriju kao pravom Arturu, to ne isključuje i druge moguće čimbenike u stvaranju mita. On pouzdano nije onaj Artur iz 5./6. st. koji se borio protiv Saksonaca i pomogao da se u Britaniji održi rimska civilizacija. Ipak, borba protiv Kaledonaca u tom ranom razdoblju mogla je ostaviti, svjesno ili nesvjesno, nasljeđe koje je pretvorilo život velikog britanskog (ili rimskog) vojskovođe u mit i legendu

Preparation and properties of poly-lactic acid, nanohydroxyapatite and graphene nanocomposite blends for load bearing bone implants

Naturally, bones have a remarkable capacity to regenerate in case of minor injury and continuously remodel throughout an adult life. However, major injuries involving the load bearing bones, such as spine, hips and knee, require orthopaedic surgeries. These bone implants are made from biomaterials. As a result, this study investigates the use of biomaterials such as poly-lactic acid (PLA), nanohydroxyapatite (NHA) and graphene nanoplatelets (GNP) for applications related to bone implants. In this study, NHA was synthesised using precipitation method assisted with ultrasonication. The process parameters (reaction temperature, ultrasonic time and amplitude) were optimised using response surface methodology (RSM) based on 3 factors and 5 level central composite design (CCD). Upon characterisation, the synthesised NHA was confirmed to mimic the HA present in the human bone both chemically and morphologically. The synthesised NHA was then compounded with PLA matrix via melt-mixing by varying the NHA loading (1-5wt%). The impact strength of the PLA-NHA nanocomposites increased with NHA loading, attaining 21.6% enhancement in comparison to neat PLA. In contrast, the tensile strength and modulus of the PLA-NHA nanocomposites exhibited an initial increase of 0.7% and 10.6%, respectively, for 1wt% NHA loading, but deteriorated with the increasing NHA loading. The FESEM microstructures of the impact fractured samples also depicted agglomeration of NHA particles and poor interfacial adhesion between NHA and PLA. Hence, to improve the dispersion, NHA was surface modified (mNHA) using three different surface modifiers namely, 3-aminopropyl triethoxysilane (APTES), sodium n-dodecyl sulfate (SDS) and poly-ethylenimine (PEI). The FESEM analysis revealed an improved interfacial adhesion between PLA matrix and mNHA(APTES), which, enhanced the mechanical, thermal and dynamic mechanical properties of the PLA-5wt%mNHA(APTES). Meanwhile, mNHA(SDS) and mNHA (PEI) had no significant effect on interfacial adhesion, ultimately, failing to improve the properties of the PLA-5wt%mNHA(SDS) and PLA-5wt%mNHA (PEI), respectively. GNP was added into the mNHA in order to further improve the properties of the PLA-5wt%mNHA(APTES) nanocomposite. With the addition of only 0.01wt% of GNP, the impact strength of the PLA-mNHA-GNP nanocomposite was increased by 22.1% (neat PLA) and 7.9% (PLA-5wt%mNHA(APTES)). Nonetheless, the tensile strength recorded a drop of 8.7% (neat PLA) and 9.7% (PLA-5wt%mNHA(APTES)). It is important to note the tensile strength obtained for the PLA-mNHA-GNP nanocomposite was within the acceptable limit of bone strength requirements. Biocompatibility of the nanocomposites (PLA, PLA-NHA, PLA-mNHA and PLA-mNHA-GNP) was investigated using in-vitro analysis. The results show the MG63 cells adhere and grow well on the nanocomposites. Moreover, the nanocomposites encouraged the cells to proliferate and differentiate within 7 days and 21 days of incubation period, respectively. Thus, the in-vitro analysis evidenced the prepared nanocomposites were biocompatible with the MG63 cells. Finally, possible extensions and future works for these prepared nanocomposites as bone implants have been highlighted

The magnitude and impact of the Youngest Toba Tuff super-eruption

Super-eruptions, orders of magnitude larger than biggest eruptions experienced in historic times, have devastated wide areas by pyroclastic flows, covered continent-size areas by ash fallout, and injected large quantities of aerosols into the stratosphere affecting global climate. The Youngest Toba Tuff (YTT) is the largest known super-eruption in the Quaternary. Here we reconstructed the ultra-distal volcanic ash dispersal during this super-eruption using a computational ash dispersal model, which provides insights into the eruption dynamics and the impact of the event. The method uses a 3D time-dependent tephra dispersion model, a set of wind fields, and several tens of thickness measurements of the YTT tephra deposit. Results reveal that the YTT eruption dispersed ∼8600km3 (∼3800km3 dense rock equivalent, DRE) of ash, covering ∼40 million km2 with more than 5mm of ash. These new fallout volume estimations indicate that the total volume of the material erupted (including the massive pyroclastic density current (PDC), 1500km3 DRE, deposits on Sumatra) was ∼5300km3 DRE. Simulation results indicate that the eruption had a very large mass flow rate and that the umbrella cloud, associated with the eruption plume, spread as an enormous gravity current around the neutral buoyancy level. The YTT tephra forms a key chronostratigraphic marker in the sedimentary sequences, and is particularly useful for constraining the age of the palaeoenvironmental and archeological records, and synchronizing these archives to investigate temporal relationships. These new constraints on the extent of the YTT deposit are therefore particularly useful for cryptotephra studies that aim to find nonvisible tephra layers for these chronological purposes. This method used to constrain volcanological parameters of eruptions in the past provides insights into the dispersal processes, and allows the amount of volatiles released to be estimated which is crucial to assessing the impact of such events

Preparation and properties of poly-lactic acid, nanohydroxyapatite and graphene nanocomposite blends for load bearing bone implants

Naturally, bones have a remarkable capacity to regenerate in case of minor injury and continuously remodel throughout an adult life. However, major injuries involving the load bearing bones, such as spine, hips and knee, require orthopaedic surgeries. These bone implants are made from biomaterials. As a result, this study investigates the use of biomaterials such as poly-lactic acid (PLA), nanohydroxyapatite (NHA) and graphene nanoplatelets (GNP) for applications related to bone implants. In this study, NHA was synthesised using precipitation method assisted with ultrasonication. The process parameters (reaction temperature, ultrasonic time and amplitude) were optimised using response surface methodology (RSM) based on 3 factors and 5 level central composite design (CCD). Upon characterisation, the synthesised NHA was confirmed to mimic the HA present in the human bone both chemically and morphologically. The synthesised NHA was then compounded with PLA matrix via melt-mixing by varying the NHA loading (1-5wt%). The impact strength of the PLA-NHA nanocomposites increased with NHA loading, attaining 21.6% enhancement in comparison to neat PLA. In contrast, the tensile strength and modulus of the PLA-NHA nanocomposites exhibited an initial increase of 0.7% and 10.6%, respectively, for 1wt% NHA loading, but deteriorated with the increasing NHA loading. The FESEM microstructures of the impact fractured samples also depicted agglomeration of NHA particles and poor interfacial adhesion between NHA and PLA. Hence, to improve the dispersion, NHA was surface modified (mNHA) using three different surface modifiers namely, 3-aminopropyl triethoxysilane (APTES), sodium n-dodecyl sulfate (SDS) and poly-ethylenimine (PEI). The FESEM analysis revealed an improved interfacial adhesion between PLA matrix and mNHA(APTES), which, enhanced the mechanical, thermal and dynamic mechanical properties of the PLA-5wt%mNHA(APTES). Meanwhile, mNHA(SDS) and mNHA (PEI) had no significant effect on interfacial adhesion, ultimately, failing to improve the properties of the PLA-5wt%mNHA(SDS) and PLA-5wt%mNHA (PEI), respectively. GNP was added into the mNHA in order to further improve the properties of the PLA-5wt%mNHA(APTES) nanocomposite. With the addition of only 0.01wt% of GNP, the impact strength of the PLA-mNHA-GNP nanocomposite was increased by 22.1% (neat PLA) and 7.9% (PLA-5wt%mNHA(APTES)). Nonetheless, the tensile strength recorded a drop of 8.7% (neat PLA) and 9.7% (PLA-5wt%mNHA(APTES)). It is important to note the tensile strength obtained for the PLA-mNHA-GNP nanocomposite was within the acceptable limit of bone strength requirements. Biocompatibility of the nanocomposites (PLA, PLA-NHA, PLA-mNHA and PLA-mNHA-GNP) was investigated using in-vitro analysis. The results show the MG63 cells adhere and grow well on the nanocomposites. Moreover, the nanocomposites encouraged the cells to proliferate and differentiate within 7 days and 21 days of incubation period, respectively. Thus, the in-vitro analysis evidenced the prepared nanocomposites were biocompatible with the MG63 cells. Finally, possible extensions and future works for these prepared nanocomposites as bone implants have been highlighted