ACER(paperbark maple)

Synonym(s)	Acer nikoense var. griseum
Common name	paperbark maple
Family	sapindaceae
Life cycle	tree (Z4-8)
Size	20-30'
Light	sun-part shade
Cultural notes	moist, well-drained soil

Slow-growing deciduous tree noted for its exfoliating bark and orange/red fall color. Ours is still small (about 18") after four years of growth. When casually inspected, the young tree looks deceptively like poison ivy, with its irregular leaf shape and red coloration to new leaves. However, the acer leaves are arranged opposite, vs. the alternate arrangement of poison ivy.
Finally, after several years in our nursery area, the tree made its way into the garden proper, replacing the silver maple that I removed from the side of our big pond's bog filter last year. A small tree is OK there, the silver maple was getting huge!

ABELMOSCHUS(LADY'S FINGER)

Common name	flowering okra
Family	malvaceae
Life cycle	annual
Flowers	yellow/black (late summer)
Size	5'
Light	sun
Cultural notes	ordinary garden soil
From seed	Germinate at room temperature (bottom heat helpful). Occasionally self-seeds in our garden. Sometimes requires hard nicking to germinate. detailed seed-starting info below

Striking, large lemon-yellow hibiscus-like flowers, deeply cut foliage. Upright plant habit. We grow it just about every year.

LILIUM

Common name	lily
Family	liliaceae
Life cycle	perennial bulb
Flowers	deep rose (July-August)
Size	4-7'
Light	sun

Impulse buy from a bulb catalog. This is an oriental hybrid lily, result of a cross between L. henryi and L. speciosum. The height range I mention is what I've found online. Ours grow stalks that are about 4' long, but they lean over so their height doesn't exceed about three feet. The flowers are reportedly fragrant, but I've noticed only a slight fragrance. The visual punch is much stronger!

ASPARAGUS

Common name	asparagus
Family	liliaceae
Life cycle	perennial
Flowers	green (summer)
Size	7'
Light	sun
Cultural notes	ordinary garden soil
From seed	we grow a sterile form

One of only two perennial vegetables we grow (the other being rhubarb), asparagus makes quite a statement in our vegetable garden. Once it starts shooting up in spring, we typically get only a few meals out of our patch, because invariably, we forget to check on new growth for a few days, at which point the shoots are two feet tall and no longer fit for eating. And they don't stop there - soon after, they are blooming, and reaching to the sky. By mid-summer, our patch resembles an enchanted forest of green upright trunks, with weeds representing the undergrowth, and bindweeds the vines climbing up the trunks. Quite a picture!

How does gene therapy work?

In most gene therapy studies, a "normal" gene is inserted into the genome to replace an "abnormal," disease-causing gene. A carrier molecule called a vector must be used to deliver the therapeutic gene to the patient's target cells. Currently, the most common vector is a virus that has been genetically altered to carry normal human DNA. Viruses have evolved a way of encapsulating and delivering their genes to human cells in a pathogenic manner. Scientists have tried to take advantage of this capability and manipulate the virus genome to remove disease-causing genes and insert therapeutic genes.
Target cells such as the patient's liver or lung cells are infected with the viral vector. The vector then unloads its genetic material containing the therapeutic human gene into the target cell. The generation of a functional protein product from the therapeutic gene restores the target cell to a normal state. See a diagram depicting this process.
Some of the different types of viruses used as gene therapy vectors:

• Retroviruses - A class of viruses that can create double-stranded DNA copies of their RNA genomes. These copies of its genome can be integrated into the chromosomes of host cells. Human immunodeficiency virus (HIV) is a retrovirus.
  
• Adenoviruses - A class of viruses with double-stranded DNA genomes that cause respiratory, intestinal, and eye infections in humans. The virus that causes the common cold is an adenovirus.
  
• Adeno-associated viruses - A class of small, single-stranded DNA viruses that can insert their genetic material at a specific site on chromosome 19.
  
• Herpes simplex viruses - A class of double-stranded DNA viruses that infect a particular cell type, neurons. Herpes simplex virus type 1 is a common human pathogen that causes cold sores.

Besides virus-mediated gene-delivery systems, there are several nonviral options for gene delivery. The simplest method is the direct introduction of therapeutic DNA into target cells. This approach is limited in its application because it can be used only with certain tissues and requires large amounts of DNA.
Another nonviral approach involves the creation of an artificial lipid sphere with an aqueous core. This liposome, which carries the therapeutic DNA, is capable of passing the DNA through the target cell's membrane.
Therapeutic DNA also can get inside target cells by chemically linking the DNA to a molecule that will bind to special cell receptors. Once bound to these receptors, the therapeutic DNA constructs are engulfed by the cell membrane and passed into the interior of the target cell. This delivery system tends to be less effective than other options.
Researchers also are experimenting with introducing a 47th (artificial human) chromosome into target cells. This chromosome would exist autonomously alongside the standard 46 --not affecting their workings or causing any mutations. It would be a large vector capable of carrying substantial amounts of genetic code, and scientists anticipate that, because of its construction and autonomy, the body's immune systems would not attack it. A problem with this potential method is the difficulty in delivering such a large molecule to the nucleus of a target cell.

What is gene therapy?

Genes, which are carried on chromosomes, are the basic physical and functional units of heredity. Genes are specific sequences of bases that encode instructions on how to make proteins. Although genes get a lot of attention, it’s the proteins that perform most life functions and even make up the majority of cellular structures. When genes are altered so that the encoded proteins are unable to carry out their normal functions, genetic disorders can result.

Gene therapy is a technique for correcting defective genes responsible for disease development. Researchers may use one of several approaches for correcting faulty genes:

• A normal gene may be inserted into a nonspecific location within the genome to replace a nonfunctional gene. This approach is most common.
  
• An abnormal gene could be swapped for a normal gene through homologous recombination.
  
• The abnormal gene could be repaired through selective reverse mutation, which returns the gene to its normal function.
  
• The regulation (the degree to which a gene is turned on or off) of a particular gene could be altered.