Epitaxial regrowth of thin amorphous GaAs layers

Channeling and transmission electron microscopy have been used to investigate the parameters that govern the crystal quality following capless funace annealing at low temperature (~ 400 °C) in ion-implanted GaAs. From the results obtained, we concluded that the crystal quality after annealing depends strongly on the thickness of the amorphous layer generated by ion implantation and the number of residual defects increases linearly with the thickness of the implanted layer. Single-crystal regrowth free of defects detectable by megaelectron volt He + channeling was achieved for a very thin amorphous layer (<~ 400 Å)

The effects of socioeconomic and cultural characteristics of regions on the spatial patterns of the Second Demographic Transition in Finland

The article studies to what extent regional socioeconomic and cultural characteristics explain spatial patterns in the Second Demographic Transition in Finland. The country’s 75 functional regions are used as area units. A summary indicator of the transition based on divorce and cohabitation is used as the dependent variable. The results show that the spatial pattern is mainly determined according to the regional level of urbanization, but the effect is mediated by cultural characteristics (secularization and support for the socialist and green parties). The cultural characteristics have only a modest independent effect.cohabitation, cultural factors, divorce rate, regional differences, second demographic transition, socioeconomic factors

Kestävä matkailu Ruka-Kuusamon matkailuyrityksissä:kestävyyden käsityksistä toimiin, motivaatioihin ja haasteisiin

Tiivistelmä. Tässä opinnäytetyössä tarkastellaan matkailun kestävyyttä matkailuyritysten näkökulmasta. Tarkoituksena on tutkia kestävän matkailun arvottamista, kestävyyden edistämiseen liittyviä toimia, kestävyyden edistämisen motivaatioita sekä kestävyyden kehittämiseen liittyviä mahdollisia haasteita. Esimerkkitapauksena toimivat Ruka-Kuusamon alueen matkailuyritykset. Tutkielman teoreettinen viitekehys pohjautuu kestävän matkailun ja kestävän kehityksen käsitteisiin sekä näiden toteutumiseen matkailuyrityksissä. Käsitteellisen tarkastelun lisäksi teoriaosuudessa esitellään aiempaa tutkimusta, jota on tehty kestävästä matkailusta matkailuyrityksissä. Tutkimuksen aineisto on kaksiosainen. Ensimmäisenä aineistona toimii kvantitatiivinen kyselyaineisto. Verkkokyselyyn vastasi 34 Ruka-Kuusamon alueella toimivaa matkailuyritystä. Tämän aineiston analysoinnissa hyödynnettiin tilastollisia menetelmiä. Toinen aineisto on kvalitatiivinen ja se koostuu seitsemästä Ruka-Kuusamon alueen matkailuyrityksen haastattelusta. Haastatteluja analysointiin kvalitatiivisin analyysimenetelmin esimerkiksi teemoittelun avulla. Tutkimuksen tulosten perusteella Ruka-Kuusamon matkailuyritykset pitävät kestävän matkailun kaikkia osa-alueita tärkeinä. Tärkeimpinä osa-alueina korostuvat ekologinen ja taloudellinen kestävyys. Myös kestävyyden eteen tehtävät toimet liittyvät yleisimmin näihin kahteen osa-alueeseen. Kestävyyden kehittämisen motivaatiot ovat usein taloudellisia, mutta myös yrittäjän ja yrityksen arvot vaikuttavat halukkuuteen panostaa kestävyyteen. Suurimpina haasteina matkailun kestävyyden kehittämiselle yritykset kokevat toimijoiden asenteet, ajan ja tiedon puutteen sekä sen, miten kaikki alueen toimijat saadaan sitoutettua kestävän matkailun periaatteisiin. Myös muiden toimialojen, etenkin kaivostoiminnan, nähdään aiheuttavan haasteita matkailun kestävyydelle Ruka-Kuusamon alueella. Tulevaisuuden kannalta voisi siten olla tarpeellista löytää jokin taho, joka lähtisi vetämään matkailun kestävyyden kehittämistä koko Ruka-Kuusamon matkailualueella. Kestävää kehitystä voisi olla syytä hallita myös laajemmin alueellisella tasolla eri toimialojen välisten ristiriitojen selvittämiseksi

The heteroepitaxy of Ge on Si: A comparison of chemical vapor and vacuum deposited layers

Epitaxial growth of Ge on Si has been investigated by two techniques: vacuum deposition and chemical vapor deposition (CVD). Vacuum-deposited Ge layers (physical vapor deposition, PVD) on heated Si substrates (≤ 500 °C) have smooth surface morphologies with a surface crystalline quality which improves with Ge layer thickness. Layers prepared by the CVD technique at 500–600 °C are comparable with the PVD prepared layers. Main defects in both PVD and CVD layers are dislocations initiating at the Ge/Si interface. Chemical vapor-deposited Ge layers grown at a substrate temperature of 700–800 °C exhibit poor crystalline quality and often are polycrystalline. Chemical vapor-deposited layers grown at a substrate temperature of 900 °C, again are good quality epitaxial layers. In this case, in addition to dislocations, stacking faults are present. All the studied layers are highly conductive and p-type. The conduction and valence band discontinuities determined from electrical measurements are 0.05±0.04 eV and 0.39±0.04 eV, respectively

A test of the effort equalization hypothesis in children with cerebral palsy who have an asymmetric gait

Healthy people can walk nearly effortlessly thanks to their instinctively adaptive gait patterns that tend to minimize metabolic energy consumption. However, the economy of gait is severely impaired in many neurological disorders such as stroke or cerebral palsy (CP). Moreover, self-selected asymmetry of impaired gait does not seem to unequivocally coincide with the minimal energy cost, suggesting the presence of other adaptive origins. Here, we used hemiparetic CP gait as a model to test the hypothesis that pathological asymmetric gait patterns are chosen to equalize the relative muscle efforts between the affected and unaffected limbs. We determined the relative muscle efforts for the ankle and knee extensors by relating extensor joint moments during gait to maximum moments obtained from all-out hopping reference test. During asymmetric CP gait, the unaffected limb generated greater ankle (1.36 +/- 0.15 vs 1.17 +/- 0.16 Nm/kg, p = 0.002) and knee (0.74 +/- 0.33 vs 0.44 +/- 0.19 Nm/kg, p = 0.007) extensor moments compared with the affected limb. Similarly, the maximum moment generation capacity was greater in the unaffected limb versus the affected limb (ankle extensors: 1.81 +/- 0.39 Nm/kg vs 1.51 +/- 0.34 Nm/kg, p = 0.033; knee extensors: 1.83 +/- 0.37 Nm/kg vs 1.34 +/- 0.38 Nm/kg, p = 0.021) in our force reference test. As a consequence, no differences were found in the relative efforts between unaffected and affected limb ankle extensors (77 +/- 12% vs 80 +/- 16%, p = 0.69) and knee extensors (41 +/- 17% vs 38 +/- 23%, p = 0.54). In conclusion, asymmetric CP gait resulted in similar relative muscle efforts between affected and unaffected limbs. The tendency for effort equalization may thus be an important driver of self-selected gait asymmetry patterns, and consequently advantageous for preventing fatigue of the weaker affected side musculature.Peer reviewe

SCOTROC 2B: feasibility of carboplatin followed by docetaxel or docetaxel–irinotecan as first-line therapy for ovarian cancer

The feasibility of combination irinotecan, carboplatin and docetaxel chemotherapy as first-line treatment for advanced epithelial ovarian carcinoma was assessed. One hundred patients were randomised to receive four 3-weekly cycles of carboplatin (area under the curve (AUC) 7) followed by four 3-weekly cycles of docetaxel 100 mg m−2 (arm A, n=51) or docetaxel 60 mg m−2 with irinotecan 200 mg m−2 (arm B, n=49). Neither arm met the formal feasibility criterion of an eight-cycle treatment completion rate that was statistically greater than 60% (arm A 71% (90% confidence interval (CI) 58–81%; P=0.079; arm B 67% (90% CI 55–78%; P=0.184)). Median-dose intensities were >85% of planned dose for all agents. In arms A and B, 15.6 and 12.2% of patients, respectively, withdrew owing to treatment-related toxicity. Grade 3–4 sensory neurotoxicity was more common in arm A (1.9 vs 0%) and grade 3–4 diarrhoea was more common in arm B (0.6 vs 3.5%). Of patients with radiologically evaluable disease at baseline, 50 and 48% responded to therapy in arms A and B, respectively; at median 17.1 months' follow-up, median progression-free survival was 17.1 and 15.9 months, respectively. Although both arms just failed to meet the formal statistical feasibility criteria, the observed completion rates of around 70% were reasonable. The addition of irinotecan to first-line carboplatin and docetaxel chemotherapy was generally well tolerated although associated with increased gastrointestinal toxicity. Further exploratory studies of topoisomerase-I inhibitors in this setting may be warranted

Epitaxial growth of amorphous Ge films deposited on single-crystal Ge

The epitaxial growth of amorphous Ge films deposited onto 110 Ge substrate is demonstrated. Substrate cleaning prior to deposition involves only conventional chemical procedures. The growth appears to be a strong function of the interface cleanliness. Two different growth mechanisms are observed: (a) a direct transition from amorphous to single-crystalline layer and (b) the growth involving the transition of amorphous to polycrystals to single crystal