The doomsday vault: Seed banks, food security, and climate change

"It could easily provide the back-drop for a James Bond movie. Deep inside a mountain near the North Pole, down a fortified tunnel, and behind airlocked doors in a vault frozen to -18 degrees Celsius, scientists are squirreling away millions of seed samples. The samples constitute the very foundation of agriculture, the biological diversity needed so the world's major food crops can adapt to the next pest or disease, or to climate change. It's little wonder that the Svalbard Global Seed Vault has captured the public's imagination more than almost any agricultural topic in recent years. Popular press reports about the ‘Doomsday Vault,’ however, typically mask the complexity of the endeavor and, if anything, underestimate its practical utility." Cary Fowler This chapter considers the use of seed banks to address concerns about intellectual property, climate change and food security. It has a number of themes. First of all, it is interested in the use of ‘Big Science’ projects to address pressing global scientific concerns and Millennium Development Goals. Second, it highlights the increasing use of banks as a means of managing both property and intellectual property across a wide range of fields of agriculture and biotechnology. Third, it considers the linkage of intellectual property, access to genetic resources and benefit sharing. There are a variety of positions in this debate. Some see requirements in respect of access to genetic resources and benefit sharing as an inconvenient burden for science and commerce. Others defend access to genetic resources and benefit sharing as meaningful and productive. Those inclined to somewhat more conspiratorial views suggest that access to genetic resources and benefit sharing are a ruse to facilitate biopiracy. This chapter has a number of components. Section I focuses upon the Consultative Group on International Agricultural Research (CGIAR) network – often raised as a model for Climate Innovation Centres. Section II considers the Svalbard Global Seed Vault – the so-called Doomsday Vault. After a consideration of the World Summit on Food Security in 2009, it is concluded in this chapter that any future international agreement on climate change needs to address intellectual property, plant genetic resources and food security.

Patent-busting: The public patent foundation, gene patents and the Seed Wars

This chapter considers the Public Patent Foundation as a novel institution in the patent framework. It contends that such a model can play a productive role in challenging the validity of high-profile patents; working as an amicus curiae in significant court cases; and also promoting patent law reform. However, there are limits to the ‘patent-busting’ of the Foundation. The not-for-profit legal services organization has only had the time and resources to challenge a number of noteworthy patents. Other jurisdictions – such as Australia – lack such public-spirited "patent-busting" entities. This chapter considers a number of key disputes involving the Public Patent Foundation. Part I examines the role of the Public Patent Foundation in the landmark dispute over Myriad Genetics’ patents in respect of breast cancer and ovarian cancer. Part II considers the role of the Public Patent Foundation in litigation between organic farmers and Monsanto. Part III examines the role of the Public Patent Foundation in larger debates about patent law reform in the United States – particularly looking at the Leahy-Smith America Invents Act 2011 (US). The conclusion contends that the patent-busting model of the Public Patent Foundation should be emulated in respect of other technological fields, and other jurisdictions – such as Australia. The initiative could also be productively applied to other forms of intellectual property – such as trade mark law, designs law, plant breeders’ rights, plant breeders’ rights, and access to genetic resources.

Enhanced electron lifetime of CdSe/CdS quantum dot (QD) sensitized solar cells using ZnSe core–shell structure with efficient regeneration of quantum Ddots

Research on development of efficient passivation materials for high performance and stable quantum dot sensitized solar cells (QDSCs) is highly important. While ZnS is one of the most widely used passivation material in QDSCs, an alternative material based on ZnSe which was deposited on CdS/CdSe/TiO2 photoanode to form a semi-core/shell structure has been found to be more efficient in terms of reducing electron recombination in QDSCs in this work. It has been found that the solar cell efficiency was improved from 1.86% for ZnSe0 (without coating) to 3.99% using 2 layers of ZnSe coating (ZnSe2) deposited by successive ionic layer adsorption and reaction (SILAR) method. The short circuit current density (Jsc) increased nearly 1-fold (from 7.25 mA/cm2 to13.4 mA/cm2), and the open circuit voltage (Voc) was enhanced by 100 mV using ZnSe2 passivation layer compared to ZnSe0. Studies on the light harvesting efficiency (ηLHE) and the absorbed photon-to-current conversion efficiency (APCE) have revealed that the ZnSe coating layer caused the enhanced ηLHE at wavelength beyond 500 nm and a significant increase of the APCE over the spectrum 400−550 nm. A nearly 100% APCE was obtained with ZnSe2, indicating the excellent charge injection and collection process in the device. The investigation on charge transport and recombination of the device has indicated that the enhanced electron collection efficiency and reduced electron recombination should be responsible for the improved Jsc and Voc of the QDSCs. The effective electron lifetime of the device with ZnSe2 was nearly 6 times higher than ZnSe0 while the electron diffusion coefficient was largely unaffected by the coating. Study on the regeneration of QDs after photoinduced excitation has indicated that the hole transport from QDs to the reduced species (S2−) in electrolyte was very efficient even when the QDs were coated with a thick ZnSe shell (three layers). For comparison, ZnS coated CdS/CdSe sensitized solar cell with optimum shell thickness was also fabricated, which generated a lower energy conversion efficiency (η = 3.43%) than the ZnSe based QDSC counterpart due to a lower Voc and FF. This study suggests that ZnSe may be a more efficient passivation layer than ZnS, which is attributed to the type II energy band alignment of the core (CdS/CdSe quantum dots) and passivation shell (ZnSe) structure, leading to more efficient electron−hole separation and slower electron recombination.

Small gold nanoparticles as crystallization "catalysts": Effect of seed size and concentration on Au-ZnO hetero nanoparticles

This work reports the effect of seed nanoparticle size and concentration effects on heterogeneous crystal nucleation and growth in colloidal suspensions. We examined these effects in the Au nanoparticle-seeded growth of Au-ZnO hetero-nanocrystals under synthesis conditions that generate hexagonal, cone-shaped ZnO nanocrystals. It was observed that small (~ 4 nm) Au seed nanoparticles form one-to-one Au-ZnO hetero dimers and that Au nanoparticle seeds of this size can also act as crystallization ‘catalysts’ that readily promote the nucleation and growth of ZnO nanocrystals. Larger seed nanoparticles (~9 nm, ~ 11 nm) provided multiple, stable ZnO-nucleation sites, generating multi-crystalline hetero trimers, tetramers and oligomers.

Advanced tissue engineering scaffold design for regeneration of the complex hierarchical periodontal structure

AIM: This study investigated the ability of an osteoconductive biphasic scaffold to simultaneously regenerate alveolar bone, periodontal ligament and cementum. MATERIALS AND METHODS: A biphasic scaffold was built by attaching a fused deposition modelled bone compartment to a melt electrospun periodontal compartment. The bone compartment was coated with a calcium phosphate (CaP) layer for increasing osteoconductivity, seeded with osteoblasts and cultured in vitro for 6 weeks. The resulting constructs were then complemented with the placement of PDL cell sheets on the periodontal compartment, attached to a dentin block and subcutaneously implanted into athymic rats for 8 weeks. Scanning electron microscopy, X-ray diffraction, alkaline phosphatase and DNA content quantification, confocal laser microscopy, micro computerized tomography and histological analysis were employed to evaluate the scaffold's performance. RESULTS: The in vitro study showed that alkaline phosphatase activity was significantly increased in the CaP-coated samples and they also displayed enhanced mineralization. In the in vivo study, significantly more bone formation was observed in the coated scaffolds. Histological analysis revealed that the large pore size of the periodontal compartment permitted vascularization of the cell sheets, and periodontal attachment was achieved at the dentin interface. CONCLUSIONS: This work demonstrates that the combination of cell sheet technology together with an osteoconductive biphasic scaffold could be utilized to address the limitations of current periodontal regeneration techniques.

Histopathological features of bone regeneration in a canine segmental ulnar defect model

Background Today, finding an ideal biomaterial to treat the large bone defects, delayed unions and non-unions remains a challenge for orthopaedic surgeions and researchers. Several studies have been carried out on the subject of bone regeneration, each having its own advantages. The present study has been designed in vivo to evaluate the effects of cellular auto-transplantation of tail vertebrae on healing of experimental critical bone defect in a dog model. Methods Six indigenous breeds of dog with 32 ± 3.6 kg average weight from both sexes (5 males and 1 female) received bilateral critical-sized ulnar segmental defects. After determining the health condition, divided to 2 groups: The Group I were kept as control I (n = 1) while in Group II (experimental group; n = 5) bioactive bone implants were inserted. The defects were implanted with either autogeneic coccygeal bone grafts in dogs with 3-4 cm diaphyseal defects in the ulna. Defects were stabilized with internal plate fixation, and the control defects were not stabilized. Animals were euthanized at 16 weeks and analyzed by histopathology. Results Histological evaluation of this new bone at sixteen weeks postoperatively revealed primarily lamellar bone, with the formation of new cortices and normal-appearing marrow elements. And also reformation cortical compartment and reconstitution of marrow space were observed at the graft-host interface together with graft resorption and necrosis responses. Finally, our data were consistent with the osteoconducting function of the tail autograft. Conclusions Our results suggested that the tail vertebrae autograft seemed to be a new source of autogenous cortical bone in order to supporting segmental long bone defects in dogs. Furthermore, cellular autotransplantation was found to be a successful replacement for the tail vertebrae allograft bone at 3-4 cm segmental defects in the canine mid- ulna. Clinical application using graft expanders or bone autotransplantation should be used carefully and requires further investigation.

Study on the elastic-plastic behavior of a porous hierarchical bioscaffold used for bone regeneration

A perfectly plastic von Mises model is proposed to study the elastic-plastic behavior of a porous hierarchical scaffold used for bone regeneration. The proposed constitutive model is implemented in a finite element (FE) routine to obtain the stress-strain relationship of a uniaxially loaded cube of the scaffold, whose constituent is considered to be composed of cortical bone. The results agree well with experimental data for uniaxial loading case of a cancellous bone. We find that the unhomogenized stress distribution results in different mechanical properties from but still comparable to our previous theory. The scaffold is a promising candidate for bone regeneration.

Design and characterisation of scaffolds for osteochondral regeneration

Treatment of joint diseases such as osteoarthritis is difficult and requires extensive developments for adequate solutions to emerge. Continued innovation in projects explored in this thesis may be beneficial to understanding the requirements of the joint environment. This may then lead to constructs that perform desirably from both mechanical and biological standpoints, resulting in complete, tissue-engineered osteochondral solutions. This thesis investigated specific scaffold designs for bone and osteochondral tissue engineering, as well as the formation of complex criteria on which cartilage hydrogel scaffolds may be assessed. The combination of hydrogels and ceramics were found to maintain chondrogenesis, while the concentration of photoinitiators in photocrosslinkable hydrogel systems may be optimised to maximise mechanical properties and cell viability. Finally, viscoelasticity of hydrogel blends was assessed using oscillatory motion, demonstrating the property is tailorable.